abbeyofrp writes a guide/graphics tutorial: lines around a PNG
This tutorial is teaching you how to do the lines around a PNG (like in my character PSD #6) in more detail than I've put on the actual download of that PNG. There are also screenshots. Please note that I am using Photoshop CS5 Portable. Please reblog/like if this was of any use to you!
Step Two) Open up this PNG on Photoshop and remove any credit on it using the eraser tool (if there is any). If you don't have any credit, right click the third box down on the toolbar and click "Polygonal lasso tool"
Step Three) On your PNG, click once off the canvas, then begin dragging it around the outline of your PNG, clicking every time you reach a corner/want to move the line. Double-click once you reach the end of your selection.
Step Four) Now, create a new layer. You can do this by simply pressing and holding ctrl + shift + n on your keyboard. Then, click Select > Modify... > Expand.
Step Five) On the pop-up box, don't change anything unless it says something other than 1px. Click "OK" once you've set it to this.
Step Six) On the new layer that you created previously, making sure that white is the foreground (main) colour, press alt + z on your keyboard to fill the selection in white. You can change this colour if you want a different colour outline e.g black.
Step Seven) On your Select menu again click Modify... > Contract and then contract the selection by 1px again.
Step Eight) Now press ctrl + x on your keyboard and ta-da you'll have a line going around the edge! If you want two lines then just right click the lines layer and press "Duplicate Layer". From this menu, you can also, when done, merge the layers together (to make them one) and make it easier to move the PNG across to a PSD or anything of similar variety.
Step Nine) Move it onto whatever you want it on. I'm just going to put the PNG on a random background to illustrate the final product.