I did two things: 1) Create (initially, force) a routine: everytime, read for 30~60 minutes before you sleep. Do that even if it is late and you're tired.

2) Try to use small moments of free time. As an example, if I have more than 30 minutes of free time, I read some pages of a book.

If you stop to think about it, you are probably going to remember recurring moments in which you had 30~ minutes of free time. Instead of using it to read Hacker News or browse Facebook, read something. Commuting is a great example.