Is there an optimum guide for spending praxis points?
Solution 1:
Realistically, it's going to come down to how you like to play the game.
For example, while you encounter a breakable wall (or two or 3) fairly early on, you also encounter a few areas where high jumping, or heavy lifting is involved, which you might not have if you opt to be able to punch through walls.
Here's a few tips though:
Getting the ability to punch through walls will allow you to get no less than 2 praxis kits (one in detroit sewers, one in heng sha sewers, and I could have sworn there was a third but I can't find anything about that). This essentially means you're getting your praxis point back plus another. With that said you can blow the same walls up, it's just much harder to spot as you won't have the wall highlighted.
EMP resistance is very useful about halfway through the game (for a very specific reason) but most places in the game (including towards the end) with electrified floors tend to have a way to get past it (like building a box bridge, or going around etc).
Near the beginning of the game, you won't find much poison gas which you need to bypass, and even by the end, it was my most rarely encountered obstacle (in fact, about half the time I encountered it, I encountered it from the other end, where I could already turn it off, because I'd taken a different route already).
The best two to get would be the ability to jump higher and carry heavier weights as these are the two most commonly encountered obstacles (even both coming at the same time sometimes.
Hacking is very useful to an extent, however some important hack-able objects have the password hidden somewhere if you're dedicated enough to look. I can't tell you the amount of times I hacked something only to come across the password for it some time later. HOWEVER hacking things grants so much exp that you'll probably gain at least 4 levels from it, off putting the cost by the end (you actually gain so much that I hacked everything I could in the game, never used a password once if I could hack it).
The social enhancer is useful, however I felt like it made the social game too easy, you don't need to do any research etc, which I found fun. However, there are a few outcomes that you'll never even have a chance to see because you need the augment, so it's definitely worth picking up by about Heng Sha, or a tiny bit later.
Those are about all that I can think of right now.