I really like the analogy that photographer/educator Scott Kelby uses to explain the difference between noodling and practicing.
He says that when he picks up the guitar, he can rock out a cool riff over and over and while it sounds great, overall he’s not getting better technically (sure, he’s getting better at that one riff). Instead, if he practices the less cool sounding (and more boring) scales, he’s actually improving his level of playing because he can apply that technique in many ways.
It’s the same with my photography. I can take a nice photo of what I’m familiar with but in order to be great, I need to practice and work on the technical things that frustrate me.
A challenge that I often give myself is to shoot what’s in front of me 3 different ways. Whether it’s the angle, distance or composition, if I can do it in 5-10 minutes (this is very helpful when shooting weddings), I’ll have learned something. I may not love each frame but I can dissect what worked and what didn’t.