Get a professional would be my advice
15mm beads on, base coat should be about 6mm thick, you can do a very tight coat of top coat then go over that once it's picked up a bit, or if you're ok with it put it on around 12mm in one coat (don't do big strokes) then scratch back to the beads
If you do it in two coats of top coat out the 1st one on very thin as if you scratch back to it it will look s**t