BASIC AVATAR TUTORIAL
This tutorial is for a very basic avatar in Gimp, one that you can make with the bare essentials. (i.e. no downloaded brushes, fonts, patterns, etc) In order to make your own custom avatar, you first need to open the image. Go to File > New, then set the dimensions to 100 x 100. (the average limit for forum avatars)


Now, it's time to make a background. For avatars, I usually just choose a color. To do this, click the foreground color (black).

Then, just click around the screen, and move the bar to the right, to select whatever color you want for your background.

Then, pour the background to be that color. Create a new layer to put an image in your avatar. To do this, click on the blank page at the bottom of the layer menu.

Now, paste your image. You will notice that the white background still remains, so I'll tell you how to get rid of it. Select the magic wand tool, and be sure that feathered edges are enabled.

Magic Wand Tool
Select all of the white areas around the avatar, and move them to a place out of the screen. (farther than what is shown in the image below)

Repeat this with all of the white areas on the picture, and you will have a transparent image on top, with the background you chose in the back!

To add text to your avatar, simply select the text tool, and click the area of the avatar that you want the text to be in.

Text Tool
After you have typed your text, you can use the moving tool to move it to exactly where you want it to be.

It is now time to add a border! First, you need to zoom in to 800%. You may do this by looking at the option bar at the bottom of the window with your image in it. Change the 100% to 800%.

Now, using the Square Selection tool, select an area that is one pixel wide at the edge of the image.

Use the pour tool to pour the border in that area. (using whatever color you want for the border) Be sure that it is set to 100% opaque, and that the "Fill Whole Selection" option is chosen. Repeat this with all of the sides, and you have a border. Now, you need to save your image. Go to File> Save As, and be sure to save your image as a PNG file, by placing ".png" after the name of the file.

And there you have it, a completed Farfetch'd avatar!