I don't tend to take many self portraits partly because I'm an overweight balding man and I don't really like the challenge of trying to make myself look good....
Whilst the internet is rife with terrible self portraits of people posing in a mirror with a duck-face I wanted to do something a little better.
Back-lighting & backgrounds: I have a fairly straight forward white linen background that I use, it is strung up in a corner of my flat using the frame and I tend to tape it to the walls to pull it taught. As you'd expect from linen it creases, but I like the effect that can give.
Lighting: One of my friends insists that before getting into using multiple lights, you should learn to use one to perfection. Saturday I stuck to this, one light in a few positions. Sunday I set-up a background light to blow out the white background completly, and instead of using a direct light I shot through a white umbrella to soften the shadows.
Focus: Perfect focus is the most difficult thing to achieve in a self portrait because you will not be looking through the lens. Whilst using a cable release timer can assist in this you are still stymied by not being certain that what you are focused on is, in fact, you.(you can address this by running a cable from the camera to your computer to do tethered shooting, but honestly I avoid this because my flat was already resembling a spider's web) My preferred method to fix this is to use a spare flash stand raised to my height and put a hat on top of it (partly to give a better target to focus on, and partly because it looks jaunty.) Place the stand where you will be stood, and set the tripod and lens up so its perfectly positioned. Auto-focus the lens to get the focus right and then fine tune it manually if you need to. Once that is done, mark the floor with a bit of duct tape or masking tape to show where to stand and you are done.
Outfits & poses: Its easy to just use the same clothes for all the shots and not to use any props. Its an odd thing about photographers, when we are shooting models we are more than happy to ask them to wear ridiculous things and make odd faces whilst carrying strange objects. When it comes to a self portrait however we are suddenly shy and reserved. Combat this feeling, for the same reason that the most interesting photos you take have a great expression or a theme, this needs to be carried forward into your self portraits. Shoot yourself being silly, making faces and wearing odd things. It will force you to break up the trap of tried and true facial expressions that you will fall into.
Tripod: You are shooting yourself and so, unless you want an arm in the picture, you are going to need a tripod to keep your camera on....
Remote Trigger: Less important to be honest, you can make do with a ten second timer on the camera, but it is more effective if you have a remote timer (with no cord) that you can hide in one hand to take shots more closely together.
Mirrors: One last point on self portraits; something that I have found useful, is to stand close to a mirror and make faces and poses. Run through a selection of them and get an idea of how you look making faces.