All right! Another question!

I'm working on the Pirate ship texturing tutorial, and this is pretty basic, but I haven't done texturing before.

I've only started the sails, and I'm supposed to layout the uvs basically evenly, but what should I do when the actual verteses are not particularly even, because then the "checker pattern" looks distorted. Or when the faces are really thin?

Thanks All!

Side note for posting images here--does any one know a quick way to resize images in Preview and/or iPhoto? It's kind of a pain to open photoshop everytime I want to resize.