All you need to do is get some white emulsion paint and thin it out with water – it's that easy! Three parts paint to one part water should work. If you don't fancy watering down your paint you can also use Dulux Sealer for Plaster.

What is the best paint for newly plastered walls?

Ordinary white emulsion is suitable and both affordable & easily available. Start misting from the lowest point on the plaster and move up & out with your roller. The mist coat dries rapidly & this bottom up method stops you getting fat splashes of paint onto the plaster. Cut in around the edges with a brush.

What is the best thing to put on new plaster?

Mix a mist coat

A mist coat is made of watered-down emulsion paint and acts as a primer. The extra moisture gives the wall something to absorb so your topcoat should stick. Alternatively, you can use a water-based primer which saves you the mess of making a mist coat.