The best place to get critiques is in a critique group or a writing class. In these settings you will get feedback from other writers, or from a writing teacher. These are people who are (to one extent or another) studying and practicing the craft of writing. They care about why things work and don't work and have a vocabulary to talk about it. Because they are not your family or friends, they are not judging you as a person, and they are not going to love your stuff, or tell you love your stuff, just because it is yours. Most of all, they are making a commitment to you, as you are to them, to give you honest (but not cruel) feedback.
Blogs are for building an audience. They don't work until you are good enough to build an audience. Until you are good enough for your blog to do you some good, improve by reading attentively and widely, including reading about the craft, and by receiving and giving critiques in critique group or writing class. (By the way, you may find that you actually learn more by giving critiques, if you take it seriously, than by receiving them.)