Tonic Chord overuse
Have an eye out for how quickly you return to the tonic chord. Almost in every case, returning back to to the tonic chord feels like “closing off” a phrase. So every time you reach that chord, your listener’s perception will give him/her the feeling of finishing something off.
Due to unexperienced composers very often overusing the tonic chord and reaching it every few bars, the musical impression always becomes a little chunky. You can not create a soaring melody that has a feeling of epicness and grandness if you keep sneaking around the tonic. So whenever you have the urge to return to it, ask yourself if that melodic arc is doing what you want it to do or if you couldn’t do a side-step to another chord instead to extend it a little more.