For me, a picture is the easiest way to give an overall view. This is because someone can take a quick 5 second look and gauge the type of character that I wish to roleplay as. As well as this I may often accompany the picture with a brief blurb explaining a few details that may not be present in the photo, like tattoos, scars, weapons, equipment, etc.

I also tend to build characters around the images that I find so I'll end up with a few image searches on google, deviant art, or even photobucket. When it comes to using the images for a roleplay and artist copyrights... it's an image... on the internet. I'm not selling it, I'm claiming it as my own, I'm just displaying it and saying my character looks somewhat like this.
[img]http://i.imgur.com/MpEbbLE.gif[/img]

Btw, before I forget, I tend to like Artistic or Anime pics. They're usually characters that have a better body position or appearance in my opinion compared to what a real life person can portray themselves as. In saying that the last character I created used a real person. [img]http://i.imgur.com/i0148Sl.gif[/img]