I've done a lot of self-timed photos. Take a look at my gallery. Unless I specify who took the picture they are ALL self-timed photos. It can be done. You need to really think about what you want to do and be prepared for a lot of bad pictures to get a few good ones. I 'mastered' this one summer when it was too hot to go outside.
It can be a cool way of getting pictures if you don't have a friend who is a good photographer or if all your friends want to be in the shot.
My best advise is to experiment a lot. This will give you a better understanding of your angles (I would never stand that close to the camera in a full skirt like that) and you'll know what your camera can do. Play around with the settings on your camera.
If I was a cosplay, a perfect cosplay, how would you know it was really me?
The Thing (1982)
(the missing word was 'imitation')