Keep in mind that the only way to get high prices on your auctions is to get lots of bids. You get lots of bids by attracting lots of buyers. You get lots of buyers if your auction is easy for them to find.
Although it is absolutely necessary to have your items listed in the correct Ebay category, many buyers don't search this way. Many people simply type the name and/or size of what they are looking for into Ebay's search box. You can increase your chances of your item showing up in their search results by having the most "searchable" keywords and by optimizing the space that is available to you in the item title. Ebay recently made this a little easier on us by allowing us to use more characters, so lets not let them go to waste! Make your title work for you!
Here are some basic rules:
1) Always include the name brand (most important if it is a desirable name brand).
2) Always include "NWT" in the title if it is new with tags.
3) Try to squeeze in the word "NEW" if it is new, because not everyone, especially new Ebayers, are familiar with "NWT."
4) Include the size of the item in your title.
5) If there are a few different ways to list a size, squeeze in as many as possible. For example, if the item is from Gymboree and is a size Small, list "S 3 3T SMALL" since those are all different ways that people search for the same size. Space is limited, but try to at least squeeze in a couple.
6) Leave spaces between words. If there aren't spaces, then none of the keywords will work. For example, if I am searching for "0-3," a title that says "0-3m" will not come up in my search results.
7) Do you have something that is size 6-12 months? Try writing "6-9-12" in your title, so that people searching 6=9 and those searching for 9-12 will both pull up your auction.
8) Listing something for a low price and don't have a reserve? These are really attractive to people who love to bid! Advertise it! Write "NR" for "No Reserve" in your auction title. Do this only if you have some extra room, as it is helpful, but not high on the totem pole for searchable keywords.
9) If you are listing something from a certain line, like a Gymboree or Baby Lulu line, make sure to include it in your title. People do search for specific items from specific lines.
10) If you are selling a Santa sleeper, try adding "SANTA HOLIDAY SLEEPER." For that matter, if you have room, add the word "PAJAMAS" to that since that's another searchable word. Get the picture?
11) Use all of your space. If, and only if, you have included every searchable word that applies (NWT, NEW, BRAND NAME, SIZE, HOLIDAY, NR...) you can add interest words like "SO CUTE!"
Here's a little test. See if you can tell which titles are more searchable:
1) a) "NWT NEW Baby Lulu Hibiscus Dress 12-18"
b) "Adorable NWT Baby Lulu Hibiscus Dress 12-18m"
answer - a
2) a) "NWT NEW Vintage Gymboree Outfit 6-9-12 m"
b) "NWT Gymboree Oddles of Poodles 3 pc LOT 6-12"
answer - b (hint-people searching "3-6" will also pull this up!)
3) a) "NWT BABYGAP NEW JEANS. SO CUTE! L@@K!SZ 3YRS"
B) "NWT Baby Gap jeans. 3T 3"
answer - b (even though b could use some work, it is much more searchable than a) | 
