How to work out a good trading strategy?

Are there any good books with trading strategies? Is there any website with free book source for downloading, reading and learning?
So far I haven't good idea to work out a good trading strategy and want to refer to some good experience of others.

There are some here www.forex-library.com/

It's not from me, credit is due to priceaction1

It looks like the books are so old.
May I ask if there are ebook source for new strategies?

Best strategy ever: buy low, sell high.
Point is you have to understand what has happened so far (price) and what will most likely happen in the future.
Know fundamentals and technicals from keeping an eye on the news and observing price action for ages, keeping the ever reoccuring patterns..