As someone who made it a goal to read 500 books before turning 28 yrs (currently I'm 24 and read 60 books since January), I would like to share couple tips.
1.) Set a goal - If you really want to read many books, then take it serious and commit to a reading goal. How many books do you want to complete and what's your deadline? Since my deadline is April 2019, i still have 44 months to finish 440 books. This keeps me on track and motivates me to read every day. It's not important if you miss the deadline, the important part is that you have something to challenge you.
2.) Have a plan - Do you know what books you will read? Personally, I use goodreads to keep track of my reading list (600+ books and growing) and the books I have read already.
3.) Know when you will read - In order to make it to my goal I will have to read an average of 10 books per month. This sounds like a lot, but if you read consistently every day and have a good tactic, then it really isn't that much. For example, I've spread out my reading through several times of the day:
Morning: - I have made reading and learning part of my morning routine. Every morning I read at least 1 hour, and during that time I read one chapter from 3 books for 20 minutes each. The first book is non-fiction, the second is about a topic that I'm interested in and the third is about a skill I'm trying to improve (for example: photography or writing). Since most books are around 200 pages, during a month I can go through 5 - 6 books this way.
Transport/Walking - Audiobooks are a great way to go through books, especially if you listen at x2 speed. I listen to them whenever I can. For example, when walking or during public transportation, when stretching and sometimes even during food preparation. These books are usually fiction or some self-help book that talks just about one concept. This way you can easily go through 2-3 books.
When relaxing - Every month I pick up 1 fiction book from the local library. I carry it with me and read it slowly and whenever I can. I read it when waiting for something, or while relaxing on a park bench and before sleep.
College/Work related books - I'm studying programming and I try to read at least 1 book per month from my field. I read it when practicing my craft, or during breaks.
If you add all of this up, you can see that I can easily go through 9 to 11 books in a month. It took me a while to build this level of discipline and sometimes I struggle to keep it up. But, I keep trying and slowly I'm moving towards my goal.
4.) Maximize memory retention - When you read this much, you will struggle to remember all that you have read during a month. In order to increase memory retention, I do the following:
Take notes while reading - I only take notes during my 1 hour morning session. The books I read during that time require maximum attention and taking notes helps me to stay focused. I don't take notes for fiction books, and for audiobooks I use smart the app SmartAudiobook which allows me to create bookmarks at specific times.
Schedule reviews - I don't read on Saturdays, instead I use that time to review my reading notes and memorize useful bits of information. Occasionally, I also go through the notes from books I read last in previous months.
Use what you have read - When reading non-fiction then use what you have read in your own life. Self improvement books are useless if you don't take action (that's why I read only 1-2 self help books per month). Another way to use what you have read is by participating in bookclubs, or reading together with a friend and talking about the books. I choose the books I read carefully in such a way that the information from the books is useful to my current situation. For example, if I'm trying to build discipline, then I will read books about discipline. I also try to write a short summary for some of the books, this helps me remember the key points of the book.
Keep in mind that this is a highly personalized method and it only works because I structured it around my own life. I travel a lot with public transit and this gives me a lot of time to listen to audiobooks. And since I really enjoy reading, it's no problem for me to read this much (Initially I wanted to read 2 hours in the morning, but then I realized that I have a life)
Lastly, I can only read this much because I'm choosing books that are relevant and useful to my life and about topics that really interest me. For example, this month I'm trying to build my discipline and improve my writing, that's why I'm reading 3 books about discipline (of which 2 are audiobooks) and 2 about writing. The other 5 books are 2 fiction books, 1 about meditation and the other about a diet and 1 book about Python programming which I'm using mostly as a reference during lectures and when programming.