I just mailed 5 dozen cookies to my husband and his soldiers. I sent some plain peanut butter, peanut butter kiss (using the carmel in the middle kisses), oatmeal/cranberry, chocolate chip, and sugar.
I also sent about 4lbs of dipped pretzels. I used milk chocolate, white chocolate, chocolate/carmel mix.
3 batches of rice krispy treats some plain, some with red & green m&ms, and some with chocolate chips.
You can also make peanut clusters or tons of different kinds of fudge. Mini loaves of fruit breads or different pastries.
I put my stuff in tin and then tape the tins tightly and using the flat rate 7.70 shipping box from the post office.