Theme? GATO.
JUST DRAW. Your art says whatever you felt your heart wanted out in that moment, like all creative endeavors. It's feeling. Just put your pen to the paper and everything will fall into place. Dont try linear, railroaded results to match some unspoken theme for the people. Dont fall into a stifling box! Just have fun, thats what it means to create.
Osaka
Perhaps you should write down 5-10 things that inspire you or that you gain motivation from, and in turn get a creative spark that gets the muse-juices flowing.
This way, you'll always have a mini record of what it is that drives you to create art, and this would also help with your issues regarding consistency. Art itself doesn't have to be confined to "making sense", as you've stated.
There are plenty of unorthodox artists over the many millennia of human history that have been so left-field & strange and have been revered as influential figures in their field, just look at Jean Michel Basquiat for example.
To motivate me creatively in my real life endeavors, I generally pull from musicians I'm listening to at the time, and transform the spark of inspiration into alchemical goodness.
Hope this advice gives you some thoughtful ideas :)
SouSTAR
@Osaka
Oh, by "making sense", I didn't meant literal sense!
Looking at Jean Michel Basquiat's art, his art do make sense : he have a consistent color palette and composition, and he use his unusual style to portray abstract emotions. But we can still see what is happening in his paintings, just not completely. It's very amazing!
I'll try to write this list :)
I often listen to music while drawing too! A lot of people do that :3