Follow-ups are crucial. This is another tactic I borrowed from my friends in biz dev: follow-up two or three days after your original e-mail (weekends don't count).

What's a follow-up look like?

Hey FNAME,

Hope you're doing well! Just wanted to follow-up with this.

Sincerely,

Herbert

This is not a simplified version -- this is often exactly what I write. Your follow-up is simply meant to ping the other party, and re-divert their attention back to your original proposal. Often times, bloggers and editors are busy as hell. That means that one or two e-mails may slip their mind, so give them the benefit of the doubt.