smooth finish coats

[toby2005]

I am trying to finish off a bathroom and in the process of putting up my last coats of compound.
I have put up two coats already. I used the lite compound. Unfortunately I am unable to get a smooth finish coat.
It seems whenever I go to get that last coat it needs some sanding, when I try to lightly sand it,
I get deep scratches that I can not avoid(it seems too soft). I am trying to put a top coat of all purpose compound and see if I can get that to sand smooth as it seems a little harder.
Any tips would be appreciated.
Thanks

[Snoonyb]

Usr topping and a 12 or 14" knife.
Mix the material to about 1/2 of the viscosity as it comes in the container.