Ive sold on ebay for years or as i call it now "feebay" and you really have a great window into many eyes which can maximize profits. But as Alan11 says below...all those tips are 100% true. Small collectibles that are easy to pack usually promise the most return.
Do your research! Go filter "sold items" of the same style to get a feel for where you might land in the market. Heck, sometimes i dont even know what im selling until i search for initial names, product numbers, etc.
Good luck!