Read more forum posts here. Blog comments won't work at all.

Few things regarding blog comments
1. 95% of blog comments are nofollow
2. Easiest do-follow comments are intensedebate
3. Now a days blog comments give very little positive value to the rankings
4.If you are doing blog commenting use your real name.
5. When you are going to comments on blog posts add some values and thoughts to the community

1) If you run a tech blog and get a backlink from a blogging tips blog that should be okay. Just try to get the link inside a blog post on that site which is related to tech in some way. One solid text link in a blog post will probably be better than a sitewide link.
2) Blog comments don't really work anymore. A big reason is because they're nofollow and also because of all the spam. You should look into link pyramids and using web 2.0 sites or building a little bit better quality.

It will not be good to depend up on the blogging tips blog and tech blog itself because, there are more number of various link building techniques are available besides the blogging. So, it is up to you about to which extent you have been using the various link building techniques available.

better find do-follow website/forum to make back-link