Does anyone have any tips for quickly acquiring and maintaining CA stacks without pre-stacking? (ie proper Deception use and positioning, optimal range, etc.)
I usually don’t even bother with CA and just go into maps with Pimpernels but lately I’ve been trying to use this skill more, especially with the Lyuda. However, I’m not so good at it - I often miss shots. Granted, last night I was in the Fridge, so rats are probably not the best targets due to their stance / speed.
Basically to use CA without pre-stacking and not in raid boss fights: get an accurate and with fast fire rate sniper, aim as well as possible and keep acumulating critical hits. It is essencial to always know where the enemies are, how many are there and how far is the next area with enemies. The basis of using CA is first acquiring and then maintaining them. It’s hard to do that, especially on regular gameplay (that’s why I favor Pimpernel on regular gameplay with Zer0).
It’s important to have these notions:
First of all, the Fridge isn’t the best place to start learning about in-battle CA 
Lynchwood is more adequate.
Darth’s offering some very good information. But I disagree with one aspect: it’s not hard at all, it’s just the setting(read: the area) should be appropriate.
It is hard, even I have trouble with CA manegement and I play Zer0 like all the time…or I just suck with CA XP
Usually I just take whatever I get as a bonus to my damage, not the foundation, since (without pre-stacking) I’m usually starting from scratch whenever I move between camps anyway. 
You can use CA glitch if you want to maintain stacks for a short amount of time(5 minutes, just like DarthSpiderDen said), but pre-stacking is required:
Also with this glitch stacks won’t automatically decay, if you switch to non-sniper weapon, go to menu, vendor machine or any other things what can force them to decay. Basiclly stacks will decay instantly, without chance to maintain them, if you won’t be holding sniper rifle in your hands. That’s how game see it.
One thing to keep in mind is that CA doesn’t penalize missed shots and rewards speed; it’s more important to shoot quickly than to make sure each shot is a crit. Sheer volume will increase your CA count faster and maintain your stack better than going for a perfect shot every single time. And as you practice, you’ll naturally get more crits than not.
When I’m using CA, I generally fire from the hip 99% of the time, scoping is too slow if you’re trying to increase/maintain a stack while working through a map. Also try to pull off at least 2~3 shots at a time, with the expectation that at least 2 of them will be crits. That requires some comfort/familiarity with how the recoil of your gun works–again, practice will help with that.
Distance…I guess mid-range, but that’s kind of vague. You know that nomad that pops up across from you in the first room of the Bloodshot stronghold? for me, that’s the closest I want to be to an enemy. Farthest would be just outside the effective range of enemy SMGs, ideally with some cover nearby in case some dick spawns with a vladof sniper. IMO that’s the ideal range for quickly aiming w/o scoping.
As for Deception, I like to engage mobs first, then throw out the decoy when they close in to regain space. Pretty simple.
I mostly use dahl and vladof snipers for their stability and speed, respectively, when hip-firing.
It’s mostly about time management… How quickly you clear a zone, get to the next, how well you anticipated your impending stack loss between crits (ie did you stack enough to compensate?)
Time= damage in unorthodox and abstract ways… Keeping track is not easy compared to pimping.
Look who’s back 
I’ve made a video about in-battle CA, but it’s failed to upload 
So probably later.
What’s up dude?
Toying around with the idea of really coming back… Borderlands needs me… The movie, bl3…
I really want to get involved… I’ve ignored the musings I have around this IP for too long.
I haven’t played for ~5 months, and the game feels super-fresh now. And, as I recall, you’ve been away for a lot longer than that.
too long…
I know I’m late to the party, but somebody suggested Lynchwood as a good place to practice gaining CA during a fight. No. It’s not even close to good if you compare it to the Friendship Gulag or other Loader-heavy areas such as Hero’s Pass. Fighting through those maps will give you a very good feel for how long stacks hold between crits, and how much combat stacks can survive before time is up. Since crits are so easily acquired, these two maps will really help you get the hang of using Sniper Zer0 to his full potential.
Good stuff… The crystalisks in the warriors lair trained me…