What you needRegular poster paints
Small art paint brushes
Primer or emulsion paint.
Go to car boot sales, or yard sales and buy an occasional table that has a smooth but unattractive surface.
Prime with primer or emulsion paint.
Either draw free-hand or transfer a drawing with tracing paper onto the surface.
A good design is to take world flags and jumble them up and copy onto the table giving an international feel, or perhaps a big sun face with stars.
Paint in the flags or design with regular coloured poster paints or gauche designer paints (watercolour paints are not really dense enough and the primer and brushstrokes show through).
When VERY dry cover with 2 coats of regular primer either satin or gloss.
You can even paint the legs of the table. Everyone will admire this unique piece of furniture and yet it came from junk.