The first shirt was for the band Chicago, and bands always give you great keywords to use: band, tour, rock, etc. This wasn't a tour shirt, but it had a quote from a song lyric, which made it stand out from other shirts, I think.
Let me say here that I seldom pass up a t-shirt from a tour--people love to buy tour t-shirts, and by nature the shirts are limited edition. Mostly I've had a pretty quick turnover with the tour shirts I've bought, but I've had a couple that I probably shouldn't have bought. (But maybe someone will come along and buy the Taylor Hicks Soul Patrol tour shirt I've had listed for a few months now, which will make me eat my words!)
Anyway, I think part of what helped the Chicago shirt sell was that it was easy to come up with a title filled with words that somebody who wanted a retro rock tee would use in their search. Likewise, the other tee from that same shopping trip that sold this week was this one for the Christian Motorcyclists Association.
I remember reading that one sign of a great eBay item is having some crossover in terms of keywords so that people who would search for different things might find it. When I saw this on the rack, I felt that Christian + motorcycles would give the listing some excellent crossover potential. I also shared the link to this listing on Twitter a few times because #motorcycle is a popular hashtag, and I thought some of the people who saw it might have a particular interest in a Christian-themed motorcycle shirt.
Although I've been doing a lot of fixed price listings lately, I listed both of these as auctions, and both received multiple bids, so I was happy with the results. I feel like it's probably best in the long run to make sure to do a combo of auction and fixed price listings. There's something fun in the auctions that you miss when you just do fixed price. Having two of my auctions inspire mini bidding wars added a little thrill to my week!