Buy a small sketch book that fits in every bag that you have and that you can take with you wherever you go.
Whenever you are waiting for something (like waiting for the metro, the bus, the train etc.) you can use this time for practicing your creativity.
Start scribbling quickly. You can also try to draw with your non-dominant hand. Or draw with your both hands at the same time.
In a second step, watch the lines that you drew on your paper.
What can you see in your drawing? Is it a landscape, a flower or something abstract? Chosen one part of the drawing you can follow your intuition to continue it.
If you want you can also do quick sketches on more sheets of paper at the same time and switch from one to another.
Or you write words that encourage you with your right and your left hand. (e.g. trust, let go, be you, be brave, yes!, … ) and integrate them in your drawing. You will assert how different it feels to write with your non-dominant hand. These are very good exercises to let go the perfectionism within you.
Feel free to integrate these practices in your next painting process.