I’ve also used the watercolor paper, tin foil, celluclay, acryic modeling paste, the pre-formed Noch/Faller plastic sheet, and even wheat bran methods. And my own invention - foam board with the plastic/paper surface stripped off then pounded/pressed with a rounded tool to create troughs and crests. Cheap and easy water base - #18 by Dioramartin Some look better than others, and some are much faster to create than others. I’m always on the look-out for alternatives.
A compendium of water base methods:
https://www.shipmodels.info/mws_forum/viewtopic.php?f=4&t=37223
