Get good at shooting Manual
Biggest step for me was getting comfortable shooting manual ( SS , Aperture , ISO )
Sure the understanding exposure books are good for a starting point but reality is you really need to shoot lots in manual and experiment to truly understand
Once you have a good understanding off how all three interrelate nothing wrong with shooting in A mode ( where I shoot majority of the time )
More critically , make sure you still have some control over the ISO and SS even in A mode ( ie, make use of min shutter speed, max iso etc selection in the menus ) . This is the most underutilized feature of some of the better cameras out there
Use and understand your exposure meter
For example : I have a friend that is truly gifted with the eye for photography and video and shoots with a pro 5DMkII . I lent him a Hasselblad lens with Canon adapter for him to play with ( so everything is manual ...doesn't even step down automatically ! ) . He struggled trying to get the exposure he wanted and asked me for help . I showed him in 5 sec since its pretty straight forward . He was bewildered and amazed there was an exposure meter in his viewfinder
to help him with this. All good now but goes to show you can spend lots of time and take great pics but you simply don't understand exposure !
Further to that, with the exposure meter you can really see the difference when you change the metering mode on your camera form matrix ( evaluative for Canon ) / spot / center weighted
Learn from others by working with them...not books !
Second thing is to hang out with people who have a different style and specialty . A friend is a great street photographer , but not so much with portraits or architectural ( which is where most of my focus is on ) . We have learned form each other
I learned far more about studio lighting hanging a couple days with a product photographer than I ever did from books or online tutorials
Prime Lens
Lastly, try shooting with a prime lens , but not because I think they are sharper ( don't really want to start a flame war but lots of pro zooms are just as sharp as lots of primes out there ) , but rather it forces you to recompose and rethink the framing of the shot
Worst thing with zoom is people zoom in or out but often to look critically at the framing ( rule of thirds etc ) . With a prime, you often need to walk back or forth and I find in doing so , I also take the time to frame better , rather than just banging away and cropping in post