I send thank-you notes when I remember to. I mean, if I didn’t thank the person in person, I ALWAYS send a note – gifts that arrive through mail, etc. And I send notes for services rendered gratis – like the girls who showed me around campus when I visited Mississippi State. Most of the time when it’s from close relatives, though, I don’t.
I send thank you notes to some people. My family always gets thank you notes for presents,it is expected, but with my friends we exchange a verbal thank you. For me it depends on my relationship with that person and what seems to be more acceptable for them. Some people, myself included, don’t like to get thank you notes. I would rather have someone take the time to call me or see me to thank me. IMHO I find thank you notes to be very un-personal(?).
Just for the record, my dad (who, my mom and I agree, is the closest-to-perfect human being we’ve ever met) always sends thank-you notes, and without prodding from my mom or anything. He’s just on the ball like that.
The past 4 years I’ve been in college, so thank-you notes didn’t go out immediately – or anything approaching immediately! – but I got them out eventually. Now that I’ve graduated, my schedule is a lot more regular and leaves more time for that type of thing. I’ll have to look into this making-my-own-cards thing; it sounds like a LOT of fun! And it sounds nice and messy. 
My roomie’ll love that!
What type of materials do I need?
I send them, and I’ve taught my sons to send them too, but admittedly, it isn’t something I’ve noticed that is returned very much. I have ONE cousin who sends ‘thank you’s’ for gifts, but no one else does. It seems to be a dying custom, at least among our relatives and friends.
you can start with simple cardstock, some markers, etc. Other things to look for : rubber stamps, ink pads, glitter, vellum, embossing powders, colored pencils, various paints, um, have I scared you yet?
It’s a very rewarding hobby, but never go into it thinking 'Oh, I’ll save ** sooooooo ** much by making my own cards!" I haven’t used a store bought card in about a decade.