How and when is it wise to ask a blogger to check out your blog?

I've learned that commenting on other people's blogs are the best way to get attention from the blog traffic of another blogger. It creates backlinks to your site like by clicking your name or something and is not necessary to provide your links all over the place (I think we can make an exception for signatures maybe?). Question is, what If I wanted to contact the blogger (or author) with a proposition of adding links to me or on his site (however that's supposed to work. If someone could explain that to me a bit more about the idea). How would I do that? I'm preaty sure I'd have to be a frequent first which could pose as time consuming for like 150 blogs to earn some trust from...