Rack your brains for a bit. What have you bought, and then only used a few times? Little things, big things, name them all. I know you have some; I'm pretty sure everyone does.
Here are some of mine.
Golf clubs. I bought them before I moved to California in 2001, and I've only used them a handful of times in Vancouver, another handful at driving ranges in the Bay Area, and a few games. I really should play more, but golfing in Taiwan is too pricey.
Bluetooth headset. Okay, this was a gift, but still. I thought I would use it a lot more -- and for the first while, I used it a lot -- but trying to keep it properly paired with my computer (for Skype) and sometimes with my phone (as a handsfree) proved to be too difficult for the little thing to remember. So as a result, it's now a permanent fixture on my bedside stand.
Spice magnets. They're these little things are small metal canisters with glass tops, designed to hold your spices while also being fridge magnets. Very cool. And on sale at half the regular price, I had to get them, dammit! But two problems that I hadn't thought of: the magnet and the metal are somewhat flexible, but the glue used to bond them isn't. So any time you happen to smack it by accident -- it's on the fridge after all -- not only does the canister fall, but the magnet part comes off. Incredibly frustrating, and none of them have ever held any spices in my home.
Various clothes. I like to buy clothes when I can envision wearing them in the future; I don't have to immediately go home and then model it, pairing it with whatever else in my closet it would go with. Sometimes it means I'll buy it without a particular wearing event in mind, and even have it still in the packaging. Weeks or months later, I'll come across it again, and find I have something "new" to wear! It's like Christmas, I tell you, and it makes me happy. What.