First start off by blocking out the area you dont want to be painted with your masking tape. Its best if doing a pattern to use a ruler and pen to ensure its going to look equal.

This is what mine looked like once I had blocked it all out.

Take the time to smooth down all of the tape making sure it isn't sticking up anywhere :)

Start to apply your paint, moving away from the tape to minimise bleeding.

It may even help to dab it on

Leave the paint to dry..................

........and finally peel off all of the masking tape. Once you have done this should all be done.

If you find some of your paint has bled just use some white paint (or paint of the colour of your background) to tidy it up :)