How I read

As a writer it is essential that you read the work of other people. It is good to read classics and modern masters to be inspired: to see how writing should be executed.
But it is also good to read books by independent authors who have often self published. These books are often far from perfect. 
It is good to read stuff like this because it makes you analyse - 

• why is this dialogue not working?
• why is she using the passive voice?
• the plot didn't make sense at that point? What would I have done instead?
• why did that character not came alive?
• why does that development in the plot seem completely unbelievable?
• has she succeeded in creating locations that I can relate to? 
• how would I have handled the descriptive passages differently?

Reading second rate novels thus becomes an aid to writing by learning from other peoples mistakes. You can go on from here and write book reviews in which you condense these thoughts into review articles.