Don't infuse meaning into your art. Ignore your horoscope. Use colors that clash. Start a series and then change your mind. Use non-trendy hashtags. Stick to your designated style. Draw circles with a compass. Make stuff that makes you frustrated. Allow stuff to go awry. Use obvious, cliché, campy, superfluous elements. Or do just the opposite. We all make rules for our art. Just remember to challenge your assumptions once in awhile.
By the way, I've not stopped making index card art - no reason to stop! In fact I'm on a super serious creative roll. And when you are on a roll, just go with the flow. These are all 3x5" index cards that I neglected to share in the flurry of the Index-Card-a-Day Challenge.
The cards keep materializing like magic.
"My head is bursting with the joy of the unknown.
My heart is expanding a thousand fold."