Mmmm, I think I write about 20 cards (not many of my friends live near by), although the list does tend to be quite fluid. If I don't hear from someone for two years on the trot, then that's it - I always put return address on the back of the envelope, so there's no excuse.
I always put one out (along with a box of biskits) for the postie, the bin men, the guys on the recycling truck, and my usual till ladies & gent in Tesco always get a jar of homemade preserves.
As for presents - it's just mum and me here. I always buy mum something that she collects and mum gives me some money and that's fine. I get a few small gifts from friends (books, silly socks and the like) and I send something homemade in return. That's the best thing about giving homemade foodie gifts - everyone loves them and it's always something tasty.
Have received my share of useless / irrelevant tat when I was younger, just because family and family friends and acquaintances felt obliged to give me something, without thinking about what I might actually like. I'd rather have just had nothing than some of the things I ended up getting.