Is the blog new? Anyway, here's some options: - Add a link/mention from your social profiles; - Earn links from 3rd party sites; - Keep publishing content regularly; - Try the "Fetch as Google" option in GWT.
If your site is not new, was it in the index before? If it was and not now, you may have a big problem. It is difficult to tell you what to do with limited information but I normally move on if my site is de-indexed.
if its not a new website. Have you trying to add a new content ? Even tags nor category. everything could be getting indexed in google as long as you know how to asked googlebot to crawl and index your pages.
1. Submit blog’s sitemap to Google’s Webmaster Tools. 2. If you submitted sitemap than check in Webmaster Tools how many web pages you submitted and how many pages Goggle indexed. 3. Type in Google: site:www.mysite.com and check your links. 4. Check your robots.txt file.
The problem is that once your site is blacklisted it would be very hard for it to rank anymore, even if you get it indexed again.