We made hot cocoa mix and marshmallows as holiday and New Years gifts for our friends and family this year. The supplies were cost effective (which is essential seeing as we've moved back to Austin from Brooklyn earlier this month and don't have jobs yet) and the leftovers are interchangeable for other cooking projects.
We used the following ingredients/ratios for our cocoa mix:
3 cups dry milk powder (I think all the options out there are non-fat, but let me know if there are other options)
2 cups powdered sugar
1.5 cups unsweetened cocoa powder
1.5 cups mini bittersweet chocolate chips (or regular-sized ones chopped up)
1/4 tsp salt
Include a little note with your kit that tells people to use three heaping tablespoons of mix for 1 cup hot milk!
The recipe/method for the marshmallows is on my blog, The Hip Girl's Guide to Homemaking.
We, of course, had to test out our present a number of times. (Quality control!) Cheers!