I firmly believe anglers who want to go to the next level should purposely change their perspectives.
What this means is getting out of the comfort zone and looking at fish in a different light.
If you only fish in saltwater, try some bass fishing. If you are a big lake angler, spend some time on ponds. I believe 75 percent of the behavior of fish is the same no matter the species so by varying which species you pursue you can pick up things to help you with other fish. I have used tactics on crappie for flounder many times and even studied walleye to get better incite on speckled trout.
I am a scuba diver and over the years some of my greatest learning strides on fishing came while encountering fish in their aquatic environment. Get out, change things up and learn something new. Your fishing will benefit in ways that will amaze you.