i always fill up to the edge first coat then i trowel up it with the trowel at 90 to the bead, second coat is always mixed a bit thinner than the first and goes on real thin but covers everything...
i seen a lot of not very good spreads layin on real thin both coats and they get this scooped effect, opposite to what youre on about... to be honest, only time i get a slightly ronded edge is when i aint skimming round the corner and just use the existing bead on an overskim...
and i always kepp the beads clean too... i seen a lot of people cant be arsed and it just looks crap....