I felt like I'm slacking off my efforts to improve my English, so I need to step my game up to develop it. Repetition helps to improve speed, build confidence, and strengthen the connections in the brain that help us learn. 

Zig Ziglar, a motivational trainer, said that "Repetition is the mother of learning, the father of action, which makes it the architect of accomplishment." 

I agree with this opinion, but then once we get used to doing it, it doesn't work effectively. Choosing methods of practicing makes a big difference to boost skills. After mastering the basics, try the advanced activities.