I love sending and receiving mail! Especially while I am away at college. It's nice to know that someone back home is thinking of you. I personally love homemade cards and think they show a little extra love.
You can buy everything you need to make a few cards at Walmart or a craft and hobby store. I usually just use extra scrapbooking supplies that I have on hand.
Here are a few simple designs that you can adapt and use.
These are a little more time consuming because of the shape.