How do you assess someone's Github profile?

From programmers.stackexchange.com:

"Lots of people in the open source community say they strongly consider a candidate's Github profile when hiring.

I'm active on Github, with a few projects of my own and some contributions to others. But looking at my own profile as if I were an employer, I see a lot of noise: projects I cloned but never contributed to, etc. The projects and patches I'm proud of don't stand out.

If you assess people's Github profiles, how do you do it? And as a developer, should I do anything differently - for example, delete cloned repos I'm not actively working on?"