3-D Flowers in Coasters

Hi there—I’ve watched untold numbers of YouTubes and still can’t get the 3-D resin flowers to work. Either the white resin sinks to the bottom of the mold or it disappears completely. I’ve tested with .5-2 oz of resin and mix it with 1-4 drops of Castin’ Craft white liquid pigment. I use a silicone brush tool or a pastry bag to shape the loops that are supposed to become petals as they settle and flow through the base. I’m not coloring the resin base, just using heated resin (heated to remove bubbles with a heat gun or butane lighter). Is it that I’m not waiting long enough for the resin base in the coaster to thicken? Most often the white resin just sinks like a squiggle/blob to the bottom of the coaster mold (which is supposed to become the top). I know this has to be the balance of consistency between the base resin and the white resin, but I just can’t figure out the trick! It’s so frustrating because I’m wasting a not insignificant amount of resin as you can imagine. Any advice would be greatly appreciated.