When backpacking, I do not use a bladder, preferring to drink out of bottles. I find I can monitor my intake much better with a bottle. I also carry some empty 1 liter pop bottles for camp duty. I find them much more convenient than my friends who use bladders. I like to drop my pack at breaks more often than most. Because my principle water source is on my belt rather than in pack, there is less chance of wandering away for a looksee and getting stranded without the water. (accident, etc.) If I am expecting long dry stretches, I also throw in a couple of 1/2 gallon plastic juice bottles. Some hikes, such as stretches on the Tonto trail in the Grand Canyon may require carrying up to 3 gallons of water between springs. A check with the Rangers usually lets me know what to expect but in the dry areas, I stay prepared to carry that much if necessary.
I also carry a couple of pint nalgene bottles. One is my "mix" bottle for powdered drinks, hot chocolate, etc. I fill half way, add the powder, then shake well. Half full gives the liquid room to mix better than full. After shaking I add the rest of the liquid. The nalgene works well with both hot and cold. For general flavoring, the great value packets at Walmart work well. If I feel the need for more energy, I prefer poweraid or gatoraid but also carry some stronger stuff like FSR's packets. Basically, I let my body tell me which would be best.