The key is consistency. Either you are a tech guy in love with e-lessons or a conservative learner who likes the smell of the book, you have to sit down (or stand up depending on the activity) to have a progress. Having too many methods, too many lessons, too many books does not help. One needs to find a method and stick with it. If it's not working, it's always can be changed. But if you try too many methods at once, all will fail and you will left with nothing to work on.

There are great mail lists to subscribe, giving great tips on productivity. Farnam Street and Greatist comes to mind. Also Medium always has great reads on this topic. Just subscribe to daily or weekly e-mail list and select productivity tips and you are good to go!

Cheers.