Most ebayers will tell you they fell into their specialty by accident. You find a what you think is a great deal at a garage sale, and suddenly you research enough to be a bit of a specialist on that category of items.  And that is what you begin to look for in the future. 

Or your child finds a hot toy that is hard to find and suddenly you are looking for the same items to slap on ebay to make a tidy profit. 

Some ebayers will tell you that you need to stick with one area of expertise in order to maintain credibility. I disagree.  I "specialize" in several very different items.  But here is a couple tips if you are listing very different items.

* Consider having like items end on the same day or at least the same time. That keeps them together when a potential customer searches when looking at your other items.. 

* Create a username that doesn't pidgeon hole you into a category.   Don't call yourself "TheHallmarkGal' if you sell Tamagotchis and Political posters also. 

* List in your auction what other items you have in the same category. If a potential customer clicks "see my other items" and sees a bunch of stuff he or she isn't interested in, he may just click back and forget it.