Also consider what kind of biomes you would like near spawn, or the theme of the map (like an island) and try a few map seeds until you get one suitable, or look at seeds others have used. A spawn covered in snow can be really annoying. Or you may like extreme hills which make some spectacular landscape. If building large structures you may prefer wide open spaces.
You can also use pre-generated maps as a base to build from. I used a Hogwarts map as a start on my old Multiplayer server. There are hundreds available for download.
Themed expansions and other mods are also relatively easy to drop into the mods folder.
Last edited by HenriDeacon; 7th January 2013 at 08:50 PM.