Well, I haven't been collecting as many ponies lately, mostly because of the bad lineup this year, but I have been making quite a few customs. I started making customs a little less than a year ago, and few and far between at that. But recently I've been doing a lot more customizing. I enjoy it immensely.
A very fun thing that I just did was participate in my first custom swap over at mlparena.com. It was an anime/manga swap.

I put out a list of the characters I liked, and I got someone else's list. Unfortunately, I really didn't know any of the characters on my partner's list, so I just had to pick which one I thought I could do the best (They were all pretty complicated). I ended up creating
Iria from Iria:Zeiram the Animation. This was the most sculpting I think I've done, with a lot of little details to get right. I had to modify the outfit somewhat to form to a pony body, so that was another challenge. I used Sculpey for the armor, painted it with acrylic paint and then put a gloss varnish on it to make it shiny.

The only disappointment I had with this pony was the hair. I don't think it looks great, what I really should have done was rerooted it all over her head to give it more body. But I've never done that and was kind of nervous, plus I had a time constraint and was cutting it close. So I ended up using hair wax to try to get it to stick up correctly. The beads were a bitch, too. I really did not know how to make those beads, I ended up just wrapping some clay around sections of hair and painting it. I couldn't harden the clay, though, so it's not the best job. If I were to do it over, I would use air dry clay for that part. But now I know. I learn new stuff every time I make a custom.
So what did I get in return? REI!
My partner did a GREAT job on her. Everything is perfect. I can't wait to do another swap, it was a lot of fun.