I always get a hydration bladder pocket in my packs, all of them - I never use water bottles. I've had them leak, break, and generally I won't drink enough water if I don't have a bite valve in front of me all the time.

I put everything in the pack itself and never in side mesh pockets where they can be ripped out of the pack by a bush or fall out when I drop the pack. (But I am not always on a nice brush-free trail.)

I never put anything in a front pocket for the same reason.

Everything depends on where and when you go.
"In the beginner's mind there are many possibilities. In the expert's mind there are few." Shunryu Suzuki