Which palette does Anna use?
You can find full details of the supplies Anna uses and recommends here.
Anna uses a white ceramic palette with a flat area in the centre for mixing, and individual wells around the edge to hold the paint.
A flat, white, ceramic plate also works well and Anna used one as her palette for a long time before deciding she prefers the neatness of a palette with paint wells. An 18 cm x 18 cm square plate also provides plenty of room for you to set out all of your paints around the edge and still have plenty of room for mixing in the middle.
Whatever palette you choose, it's best to have a mixing area that's flat and white as this gives you a really good sense of what your paint is going to look like on the paper before you apply it. It helps you to be better able to judge your consistency of paint too.
Please see Anna's video here on why choosing a good palette is so important.
You don't need to worry about your paints drying out on the palette or plate, as they can easily be fully revived by adding a little water and if you're not going to be using them for a while, you can just cover the plate with some plastic film (Cling Film) to keep the dust off them.