You will need:
1/2 cup of salt
1/2 cup of water
1 cup of flour
Add the water to the salt and flour slowly.If it gets sticky add more flour, you may not need all the water. (I used all the water)
Roll it out and make the shapes.
Microwave the dough ten seconds at a time for a maximum of three minutes. If you are doing only one object that will only take two minutes max (with thick dough).
I used two methods of making the shapes I wanted. The first one was to put the dough in a thin plastic mold of cars. In the microwave I was only able to do this for one minute before it started showing like it was going to melt. I should have done it for only 30 seconds, which I did for the second batch. For the rest I did hard plastic cutters of a cat, fish and duck. Those were fine for one minute and then I took the cutters off. I still did them (about six at a time) for a total of three minutes but I kept an eye on them, stopping at least every thirty seconds.
Salt dough shapes cooling off
My advice is to do your first batch stopping every ten seconds and then you will have a better idea of how things are going. My dough did puff up a bit.
Leave them to cool off and then you can paint them. I used a paint provided in a kit but I think acrylic would work best. After that had dried I painted them with vanish. A bit smelly and sticky but the idea is that the paint stays on longer!
For the magnets you can buy them at art or stationery stores. I found some square ones at the Crazy store which did already have pictures on, but they served the purpose. You need to be careful that your dough is not too heavy or else they won’t be able to hold anything else up.