I try to train myself to not skim read.

Every few pages, I might take a little break, close my eyes and recall what has happened in the last few pages, who the new characters were, what did whoever do etc. My punishment for failing to remember is to go back and re-read.

If, I am skimming a lot and can't stop, I figure its probably a book not worth my time as its not capturing my interest.

Also, for me at least, if I want to concentrate on anything, whether its a book, a videogame, TV, sports game or movie, the phone has to be in anther room, its far too distracting. With reading I may see a word or phrase that I want to look up on google and do so, then spend next ten minutes clicking on more and more stuff.