Reflecting back on work

About to start reflecting back on the designs that I have done. Looking at ways I can improve highlight and change the designs to give them more POP. Perhaps I need to look at the default colour options I choose as some of the designs look better when applied against certain colours than others.
The need to shadow and highlight has arrived Dadadadadadaaaaaaa so bear with me as I lift those designs and more up to the next level.
BTW : The Numskull design looks awesome against a red t- shirt, only comment I have had is that it needs to be BIGGER