2. Do Programming
If you want to train your brain to think logically and in patterns then you should do programming. It pushes your brain a lot towards the limit, and in return, you come out a much smarter person. You can think of programming as an advanced level of solving puzzles. There are a lot of free websites which can help you to learn to programme. Besides, a lot of jobs requires programming, so it looks good on your CV when you say you know how to do it.