Learn about your camera !!!!

Read your manual !!!! Read it several times, and practice in between. If you don't have a book, download a new one from the manufacturer's website.

Attend a class, read some books, read/watch online tutorials.

The major camera manufacturers (like Canon, Nikon, Olympus etc) all have very useful sections on their website for learning about photography.

http://www.nikonusa.com/Learn-And-Explore/Nikon-School/index.page

http://www.olympusamerica.com/cpg_section/oima_learn_center.asp

http://www.usa.canon.com/dlc/controller?act=HomePageAct

http://photographycourse.net/

Understanding at least the basic principles of photography (as well as being familiar with your camera) will enable you to make the most of your gear, and will make a HUGE difference to your images.

For portraits:

Rule # 1: Do NOT make a duck face!
Rule # 2: To take a good self portrait, don't just hold the camera in your outstretched hand, that is such an awful look!
It distorts your features and screams: "SNAPSHOT !!!!!".

Make an effort to take a decent photo, then you either won't even need to edit it, or at least it would be worth while to do so.
Make sure your camera is set to the biggest possible size and the highest possible quality. Pay attention to the lighting and to your background.
Take a photo when and where there is enough (diffused) light - you do NOT want to use a little on-camera flash!

If you don't have a tripod, put your camera on a little bag of rice on top of something sturdy and use the self timer to take a much better photo of yourself.