Hello Tazen,
I am a freelance photographer in Second Life and do it mostly as a hobby and fun.
It really depends on what types of photos you are looking to take. Are you taking photos of people or are you taking pictures of a scene? Are you going to use an outside photo editing tool or just use the raw material of windlight and other such settings?
I personally do both photos of people and scenes and I really prefer to capture the raw wholeness of a photo in Secondlife. Only using windlight as my main soruce of RAWR. Suggestions you say?
Well if youre going to take photos of people who better to test out photos then your own avatar? You can pose yourself, move yourself and take photos of yourself without having to tell someone what to do. And while you are at it you can play with the windlight settings and see which you like. Ive made a few of my own windlight settings for photos but i mostly just "Edit" the one thats on the sim and play with the settings until I capture the right light and shadows. And shadows seem to be key to a great photo, it really makes a photo stand out when there is a contrast of light and dark. Also the focus (FoC length) is another tool setting you might want to play with.
I hope that all helps. I am no pro and I always see room for improvment in my own photos so its a constant learning and applying. Look at other peoples photos and see what they do. Then try and think what you could do to make it better or nicer.