If you're a collector like me, you will find yourself constantly searching for the same kind of items over and over using the same keywords. Here's a couple of easy tips you can use to improve your search:
1. You should also consider searching for common misspellings of the keywords, e.g. if you are looking for "J R R Tolkien" items, you might also want to try searching for "Tolkein" (a fairly easy mistake to make.) Many people will only search for one version of the spelling, and will thus miss items with the other spelling. You can search for both by entering (Tolkien, Tolkein) in the search box, which matches to either word.)
2. You should try searching your keywords in a foreign language, e.g. if you are looking for "autographs", you should also try "autogram" and "autogramm". Many items which are listed in national eBay sites are described in their language of origin (not everyone on eBay uses English as a first language.) You can do this on the search box by entering autogram*, which matches any keywords beginning with the letters "autogram".
You never know, you may just find the thing you are looking for... And better still, you might find the competition for this item vastly reduced because nobody else is picking this item up on their searches!