I have a bit of an obsession with these step stools. They come from IKEA with a piddly price tag of £10. The thing about them is that they are really sturdy. Like a lot of IKEAs stuff the term "built like a brick out house" springs to mind. I have one in the shop and it's in constant use but still looks like new.
The trick is to add a couple of layers of varnish after the paint has completely dried. Paying particular attention to the corners and the steps which will get the most wear.
This one is a very simple design in blank and white to match Boyfriend's kitchen. I usually use rubber stamping techniques to great effect.
I make use of old paints and reduced tester pots of mat emulsion. They make a great very cheap base coat. For the black areas I have used Acrylic paints.
Use a mat clear varnish available from DIY stores.