Pros still shoot free throws after practice. The basics never graduate.

Fundamentals are not a stage you pass through on the way to real skill. They are the thing real skill is made of, and they decay quietly if left alone, so the people who look effortless are usually the ones still doing the beginner drill years in. Advanced work rests entirely on whether the simple parts are automatic.

Name the two or three basics your whole activity depends on. Put a small amount of each into every session, even when it feels beneath where you are now. Especially then.