I found the easiest way was vacuum sealing some chocolate and sticking it in a souvee at 92f overnight. Agitate a bit after it's melted and a while before removing it from the warm water. I use the method for making tempered cocoa butter to use as seed in my tempering machine. The exact temperature varies by type of chocolate. The trick is getting it just below the point that type 5 crystals form. It's perfect to make seed chocolate for when I use the tempering machine, saves a lot of time and there's the convenience of having a big pool of chocolate for molding, it's better to have a bigger pool than you need so that when you pour out molds you can do it directly into the working pool.