i use to use the pencil tool but by holding shift ( i think it was ) you could draw straight lines. by using that all in one layer, or multiple layers, you can change the colours, thickness, and probably put some effects onto it. havn't used ps in a while so i may be wrong but thats as best as i remember doing a 2 pixel dark black border to make my sig's look tuff back 2-3 years ago!