First attempt can be fiddly and frustrating, but it very quickly becomes a simple procedure with a little practice. Definitely watch the instruction video online first (I watched it AFTER my 1st attempt…) and I'd strongly suggest using both a roller and scraper as they do – I'm just pushing the putty into the mold with a finger and slicing off excess putty with a sharp blade – that works well, but have to be careful not to cut the mold. The GSW scraper would certainly be a better option. Overall, teething problems aside, which were entirely my own fault, I'm loving this set of molds. …Great way to use up any little bits of leftover putty too.