I've recently started using the UV-light curable liquid resin. Bondic is one of the brands that makes a pen with the resin, and has a UV light on the other end to cure it - cures in a few seconds, and you can tidy it up a little bit with a toothpick or old brush before you cure it. I haven't tried sanding it and it can be a little messy - I usually put it on my palette (or a piece of cardboard) and apply with a toothpick for smaller areas - but it works great and I find it a lot less painful than preparing green stuff, etc.