I have but it has always been pretty specific, like peppermint tea, gummy bears and stationary for three particular troops I sent to.
What I find works is just going through the grocery thinking about what I'd like to have out there, knowing the limits of the facilities.
This is how I came up with the boxed drinks and small cans of fruit and applesauce.
Oh, I also had a request for saltines specifically.
The snack "combos" those little hard pizza roll up snacks travel well as does peanut butter and jelly, get plastice jars.
Some of these things add weight but it is worth the extra cost if you can afford it.
Good luck.