After painting something, offload any extra paint onto blank sketchbook pages...
...embellish further with bubblewrap, cling film, tissue papers or indeed printing that paper onto another sheet.
Look into spray inks and use them with stencils
Paint papers using a brayer. Squeeze paint onto a surface in squiggles place paper on top and roll over with a brayer. Lift off and let it dry. Repeat with more paper.