Swirl textures are among the easiest textures to do. You just have to careful not to have lap marks showing on the outer edges of your texture flow when you come back to a spot to continue on.
In my experience, a flat tool like a plasterers trowel can be used to create swirls also. Using thin drywall compound, you pat the flat side of your trowel into the mud on your hawk, then randomly pat the drywall or plaster surface with thin patches of mud. Press your trowel flat into these patches and twist the trowel. You will get swirls, large or small as you prefer.
The key is try to be random by swirling in different directions as you move across an area. Don't make the texture solid, but leave small open spaces between the strokes. This can help you avoid lap marks as you bring more texture into conjuction with texture already applied.
Shoot for doing small areas at a time. I usually keep it to about a foot and a half square (roughly) before I start swirling.
It may help to apply a coat of drywall primer (PVA) over your skimmed plaster/drywall ceiling or wall before you start with the swirl texture. Over a sealed surface, the mud will swirl easier. Just be sure when you are done that you prime coat everything before you paint.
It's almost easier to do it, than describe it.
There's a webpage that has quite a bit of information
about mixing and using textures.
Linear Mode
