I wouldn't say I do it on purpose, as far I know I have never gone out of my way to specifically make an attractive character. But, my process is slightly weird. Despite being male, the majority of my characters at this point are female and I always start my sheets with two things; a name and a picture. I take a picture and write my character based on that. The personality, background, and everything else all come down to what inspiration the picture has given me. While I never focus on making an attractive character, it happens sometimes and I realize that I like the description I had written for the character to explain what the pictures don't. 

To clarify though, I stay away from anime pictures and real people unless the setting requires a real person. Both ruin my feel for a character when I'm writing them as anime pictures are far too childish looking most of the time and a real person leaves little to the mind to describe. But, I also can end up creating bland characters. Like one in a dark fantasy RP I was in which was described as bland with brown hair, brown eyes, and a homely complexion. She isn't what one would classify as overly attractive and it made sense since she was a member of a band of warriors where death was likely to happen.