1. Write your words on a separate layer from everything else 2. Select the words! (I like to select the area around them too, click "Transform", and then press "OK" underneath that) 3. (if you're working in SAI) Press Alt + S + 1 ! That will expand the area around your selection by one pixel. To make your border bigger, keep pressing Alt + S + 1. 4. Make a new layer underneath your words, and fill the selected area with another color!
Voila, words with a border! ^ u ^ Or another way to do it: 1. Write the words 2. Use the paints effect above your layer box to make a fringe!
This way doesn't work if you want to have two separate colors though. This just adds a darker shade of the color you already wrote your words in.