Well, when I started on Ebay, I started selling my own clothing and my daughters clothing that we grew out of ........ Yard sale clothing! NICE STUFF of course. I sold it in lots. You would be surprised!
Yard sales is a good start! LOL Then I found boutique stores who sold used clothing -- to deal with, and bought all the sale items - but there is so much competition now - getting the feedback up is the name of the game on Ebay. Higher feedback, more customers! :) But I can tell you, it didn't happen over night. It was hard work, but fun for me, still fun for me, and I think you can't give up!
I just enjoy the whole resale thing! It's exciting to me!