I have. I did DD2's room, and one bathroom so far. Doing the downstairs toilet next week hopefully.
I will say, I have had no training, just watched videos and thought I'd give it a go. It can be hard work. You have to finish each wall in one go, no 15 minute breaks to rest your arm and have a cuppa. Having it done professionally does look better, but doing myself costs a faction of paying a plasterer, and still looks a lot better than when I started.
I have used this;
www.diy.com/departments/diall-fine-finish-ready-mixed-smoothover-finishing-plaster-4kg/1849578_BQ.prd
It works, it does what I need, and it gives quite a nice finish.
My tips would be, prep! Make sure you pull out wall plugs and fill the holes with poly filler, and give them a quick sand back. Make sure you also sand back any bits that stick out. Drips of plaster are a pita, so dust sheets, etc. Just start on the easiest wall, one where you don't have to stand on step stools, or work around windows or doorways. Have a go, get the feel for it. Then if it's awful, sand it back (masks essential, lots of dust) and try again.
I tend to do the whole room, then give it a gentle sand, then go back over the whole thing again with a very thin finishing coat. I should probably use different plaster for the first layer, but hey, it works.
Also, finish the edges with decorators caulk after you're done and decorating. Helps the overall effect.