Annoying Hand Issues

Definitely no need for grippers here, all this typing will do it. 

Boomroasted

Grip size is a factor.  Too big of grips and you won't be able to get enough finger wrap to have a secure grip.  Too small of grips and your finger tips will not have enough room before your palm.  For a demonstration of this, try doing pullups on a large diameter bar or open handed ledge, vs. doing them on a bar that lets you have good finger wrap.  The oversized bar will require a lot more grip strength to hold onto.  I personally like 29-30mm dia "slim" grips for my size medium hands.  I'd guess that typical 32mm grips are better for people with size L/XL gloves, and the really chonky grips above that are for XL/XXL paws.

As someone with problems with nerves in my hands, I find the new Goldstone grips amazing - thin with a raised palm pad. I'd say they give me better ride comfort than Rev Grips.

1. If your glove is bunching up? Means it's too big. Could be from a few reasons. But yeah, tighten that up. 
2. Glove care. Always wash your gloves when you wash your bike gear. Kinda like lube your clipless pedals when you lube your chain. Manufacturers have always preached that sweat combined with dirt/sand, etc is the number 1 reason for gloves to die early. 
3. Gloves wear out. The can stretch out, they can get holes, etc. Replace. Save them for lawn work or football games for drinking beer, so your hands don't get cold. Be creative. But def don't ride with them. 
4. Always have several pairs of gloves in your bike bag. The ones your know you can trust. Even carry a spare set with you on large rides. They can and will expand with moisture from your hands (water crossings?) just on one ride. Which will cause the "bunching". 
5. Your blisters are from riding. That's good. Blisters cause calluses. That's good. Your special lady friend may not like your rough hands, but your riding will. 

Two other things to consider:

1. The spacing between your brake levers and grips. I used to get pain in the outside of my palm and after experimenting realised that my brake levers were set too close to the grips, causing my palm to be on the very edge of the grip. Moving the brake levers inboard (toward the stem) resolved the pain.
2. Seeing a physiotherapist. If playing around with setup doesn't resolve the pain, it might be worth also worth trying to ensure a musculoskeletal issue isn't the cause.

I'd echo:

• Don't get get hyperfocused on the area of the symptom without considering the whole system - i.e., suspension set-up, etc.
• Depending on the sports you've played, it's very easy to get hold the bars too much in your fingers.  Experiment with holding the grips more into your palm.  When I discovered this early on, it helped with arm pump.  
• I'd try this
  • Detach the shifter and dropper remotes
  • Move the brakes way in so they don't distract you
  • Find the natural place in your hand for the grip (think more barbell and less golf club).  
  • Experiment with bar roll as Robot described.  Huge component of excess hand pressure on outside of palm.  You're going to have to use roughly the same grip and wrist position to both deadlift and bench press.  You'll want to be somewhere in between those two.
  • Once you have bar roll set, then reintroduce brake levers and adapt them to your grip and bar roll - not the other way around.  Go flatter the more the bike is descending oriented.
  • Then get the shifter and dropper remotes in the best position possible.  Do everything you can to avoid moving your brake levers from the position you liked best.
  • Go ride and tweak.
  • Measure and record.  You could dismantle my cockpit and spin the reach and contact adjust on my levers, and with a level app on my phone and calipers I could have it back exactly where it was in no time.   

Also, I live in fear that Chromag is going to discontinue the squarewave.  I borderline hoard them.  After years of riding them, other grips make the pressure across my palm feel really focused on the outside.  Interesting to see the ODI elite palm bulge get more pronounced on Goldstone's new grip.  I've never understood why this hasn't caught on even more.  Pretend you're holding a grip in your hand and look at the shape of your palm.  I've tried to go to push-on's and I've grips with the rubber core cut out and such, but I keep coming back to the shape of the squarewave (but I've always like a thin, firm, fairly simple grip).

Good luck, stick with it, and hope this helps.

@TEAMROBOT nails it above - it’s best to view this as part of a system (you, posture, bike) and avoid ‘one simple trick / purchase’ solutions. 

A fit is a start, but as part of that you’ll ideally get perspective and advice on your posture on bike. Lots of expensive fits go out the window when we get tired etc if we aren’t aware of and managing our bodies. 

It is amazing how having a quick cue in mind to shake out arms, or relax neck/shoulders can help train new patterns.
One awesome resource for that is the intelligent action mtb skills workshop (online). It’s focussed on skills, but all skills are just ways to use our mind and body together to do what we want.

Also, if you’re working with your hands and arms a lot, it’s normal to carry stress and fatigue there. Finding ways to actively release those muscles makes a massive difference.  

once you do that stuff, you’ll be a better rider, and better placed to make changes and experiment. For me I’ve found a comfy bar and SQLab tech trail grips rock super well.

On suspension setup, the default tends to be "my hands hurt, make softer", which can be an issue, but suspension that moves too much too quickly can be just as much, if not more, of a problem. If you are going off features and having to fight the bike to stay into position, this will force you to put more pressure on your hands to compensate.

Also worth considering is that highly progressive forks may need more compression damping to reduce spiking. If you are blowing through the travel constantly and hitting that spike point, using it to slow the fork down, then you'll have harshness also. 

Point being, don't always default to softer. Try firmer setups also and see if that helps.

Everyone talking about the "science" of grip size. I wear size 10 gloves (Large in generic sizing) & grips nor gloves have ever caused me a blister on the MTB unless I just haven't ridden in forever. Even on hot laps days at a bike park, the only time I get blisters is if I don't take my gloves off between sweaty runs to let my palms air out. That's the #1 way to do 36 laps at Mountain Creek in a day. Do a lap. Peel your gloves off on the lift. Sweaty palms go away. Do more runs.

But this guy is dealing with external blisters in the "pull up" callouse area. So yeah, that's 2 things.  1 - Bar roll & reach (he indicated he was a bit too far back) which can be addressed by saddle & bar roll. 2 - Namby Pamby hands which can be dealt with by keeping your hands dry between runs OR....doing gloveless runs with a bit of trail dust on the palms to keep your hands dry. 

Think of it as using a shovel for the first time in a while. I'd rather have some sand/dust on my palms rather than raw dogging it. Dirt actually eliminates some of the friction from gripping & keeps prune fingers & palms at bay. And dirty/dusty hands tend to callouse over quicker than gloved ones.

If you have hand pain, the first thing I would look at is bar roll. 

Bars rolled too far forward can cause serious pain in the outer palm. In my bike park experience, tilting the bars back even a few degrees can be a night and day difference. 

The main thing I’ve learned about handlebar setup is that it’s entirely individual, so you just have to try different things. Once you find what you like, then you can go looking for the most successful racer that has their bars set up like yours so you can argue on forums.

Personally, I’m an “Aaron Gwin and I roll our bars back to be aligned with the head tube angle” guy. I find that has the most natural steering response and makes me feel better about myself.

It’s actually the opposite

Goldstone copied my bar roll. Now I argue on the internet 

A few things I have not seen mentioned that may be worth considering, just to further understand this problem, as its something pros even had to deal with in their lifetime.

Grip texturing, this can cause your gloves to bunch up a lot. At least it did for me. I found if I wore gloves I needed pronounced ridging for my glove to have good traction/grip. But this caused bunching. So if I went smooth gripped, I had less grip/traction with gloves. I settled on good smooth rubber and no gloves. More dangerous but I like my goldilocks setup.

Everyone mentions suspension setup helping. Which it can definitely help. I would like to point out that tires and tire pressure play a big part in this equation too. I get blisters from the small vibrations/movements, not the large ones where I brace and grip my bars heavily and my hands stay in place. Its the small vibrations that make my bars vibrate on the surface of my hands. If you are like me and have a stiff suspension setup, having a high tire pressure or thin casing tires (they have to have a higher pressure to risk less flatting and wobbling) can resonate that small bump sensation directly to your palms. However if you have a tough casing tire, this can act as a huge damper to small rocks and natural ground formations before your suspension has even begun to move. In turn a lot less friction on the palms. 

I know this is getting pretty deep in the weeds but this was something I discovered on accident and makes me not want to go back to trail tires. They're lighter sure, but the ride can feel like crap and translate right into your body.