Stephanie Lee introduced me to plaster some years ago with her book Semi-precious Salvage.  It contains a fairly simple method of mixing and casting plaster (like the bird head in the photo below), that worked like a dream. In later books, she showed how to use plaster cloth.
Like this:

 While browsing in a bookstore I came across a piece in someone else's book (sorry, I didn't think to write it down), where she talked about using plaster cloth this way:

You wet and wrap the plaster cloth around a piece of cardboard, smoothing it out with your fingers, then laying down a strip of plaster cloth across, and, when it's dry, applying acrylic paint. To finish and give it a smooth, glowy look, Stephanie uses encaustic. I don't use wax or encaustic, so I finished it with thick gel medium.

If you like texture, this is one way to go.

 

Simplicity is the removal of the useless and the unnecessary--source unknown

The results: for me, worth waiting for. It was a very satisfying project even though it took two days from start to finish. I especially like the organic look

Ná bris do loigrín ar stól nach bhfuil i do shlí. (Do not break your shin on a stool that is not in your way.)