How can we find comment sites or blog for Do-Follow backlinks? can anyone suggest any trick list?

commented: As you claim to be a web developer, this is not good for your profile or attracting business. -3

I would have thought that a web development outfit such as yours would already know the SEO basics such as this...

You need to find the top litas of popular sites and blogs in your niche. I recommend referring to your competitors' backlinks. You should place your links in the same place where their links are located.

search in google and even commenting sites where you can see do follow profile link list