When making avatars I recommend making some brushes that are made up of backgrounds, background effects (like doodles) and faces or parts of faces. I also recommend starting out with a large canvas (with those brushes to match that size) in about 300-400 pixels square. It makes it easier to create the image and be able to use other brushes. You can always reduce an image to the size the forum requires (usually no bigger than 150 or 100 pixels, but some are 50). Plus, create your avatar in layers. This way you can change a layer, like with the seasons, or change the person in the avatar. To save your avatar with layers, simply save as "name.xcf" BEFORE you merge layers and rescale for your online version. To save as a usable one online save as "name.png", jpg or gif. From here you can also save it as a brush if you want to use it as a stamp. When I save my avatars, I start with the original 300 pixels then I scale them down to 200, 150, 100 and 50. This way I always have the size I need. These do not take up a lot of HD space.