Issues with backlinks
 

I require some inputs on backlinks. It seems not to be so simple dealing with them & some issues came up. I have already a sizable amount of backlinks. Now it seems, however, that they are getting less. I have no clue why that is the case. I was one time not using & of those search engine optimization strategies. Could the reason be that I downloaded the webmaster tools of Google? I hope that this is not the case. Even if I have links on my net site, Google seems to ignore it. What is wrong with my backlinks? What did I do wrong? Does anyone has any advice?