I'm using Nokia Asha 200 how can I use my own picture to create theme?

u can create background with ur pic not theme.

click ur picture. click on 'options' , click 'use photo' and then set as wallpaper.

all done.

Why would a professional photographer want to apply preset edits to their pictures? Technically, I usually keep my camera set to take both a raw and a jpg copy of the picture, and my jpg copy does have a vivid color style on it. However, any pictures I actually use beyond sending a snap shot over facebook or txt, will be adjusted by hand, from the raw copy of the picture. Editing manually is better because it gives you control over the edits that are applied. A pro photographer does not need edits to make their pictures not suck. Unless you are turning your picture into a graphic design of some sort (which I often do in a very abstract form), your pics should need minimal editing.