V-I Cadences and Extensions
Final V-I cadences in important form sections (e.g. like the end of your main theme) can start to sound quite pedestrian and boring especially when they occur very often in the piece. Of course, the quality of a V-I cadence is one of the strongest structural elements in music but due to its absolute predictability, it’s not particularly exciting to hear them every few seconds.
Therefore it might be a good idea to break the expectation once in a while with for instance a deceptive cadence that doesn’t (immediately) go back to the I. In classical music theory a deceptive cadence is going from V to vi and continuing from there. However you can also extend a V-I cadence by inserting chords in between and therefore prolonging the time until it ultimately resolves to the I.
Some of the standard solutions are the following:
V-bIImaj7-I (E.g. G(7)-Dbmaj7-C)
V-IV/I-I (e.g. G-F/C-C)
V-bVI-bVII(add9)-I (e.g. G-Ab-Bb(add9)-C)
(all of the V could also be Dominant7 chords but not necessarily)
There are quite a few more. All have in common that they only work if the melody sustains on the root note after the V. If it goes somewhere else, you need to find other alternatives.
Also, you should make sure that extending a V-I cadence doesn’t break the form of your piece/musical section. An unintentional 9-bar form might be more irritating than a repeated plain V-I.