I wish I had some tips for you, but I've never used a 2 piece mold either. Here are the directions though...
To make a solid piece of candy using a two piece mold with no opening, fill one half of the mold to the edge and place in the freezer. Cool just long enough to set-up top half of candy. Remove from freezer. Fill other half of mold to the edge and then add approximately one more teaspoon of candy. Now take the half that has set-up and place on top of melted half. Clip together. Candy will bleed out of mold seam. This will assure that you won't have cracks at candy seams. Now that the mold is clipped together, turn over so that melted half is on top. This helps the two halves to adhere. Place in freezer. When ready, remove from freezer. Remove one half of mold and clean seam. Remove other half of mold and trim the bottom if needed.
To make a hollow piece of candy with this mold, fill one half of mold and clip together. Roll mold until completely coated. Place in
freezer in upright position and allow to set-up approximately three minutes. Remove from freezer and repeat this process one or two
more times. Place mold in upright position in freezer until set-up. Remove from freezer, remove one-half of mold and clean seam.
Remove the other half of mold and trim bottom if necessary.