Backlink checker

i use ranksignals(dot)com to check my competiters and my own backlinks

Good thread, i will try the tools offered. I used domain pop and blekko but since domain pop is gone and blekko is paid, I trust only my SEO powersuit

Well, I presume if you write an article about a specific product, service provided, a person sooner or later they will find out that they have been cited by another website (which is you) and likely they will contact you. If they like your post you should ask a vote in form of a link
for instance: you have a blog where you write miscellaneous things ... or you choose a category which is about blue collar workers, and you write about plumbers, how well they are doing their work, how heavy is their job and how less they earn for it, you include some photos and even a funny but not offensive video (along with links to the source site, hopefully a relevant one)

After you are done you should contact a few plumber's sites to earn some votes or just write write some comments on your article. If they accept it: Great ,
if they don't, well (you should find out why, and improve it if it's needed) you will remain with a good article and sooner or later others will find you.

I use opensiteexplorer and ahrefs - although you get more out of opensiteexplorer if you're not willing to pay...

Really important to use a quality one to understand what your competitors are doing