Horror costumes are usually worn to celebrate Halloween. The industry has grown over the last 20 or so years and some have taken it to a new level.  For those who prefer to make their own, start by taking  an old costume or piece of clothing, and follow these steps to make it look old.  Age your costume with paint that is one shade lighter than the fabric. Use an old paint brush and dip it in the paint and then paint it on a newspaper to remove any excess liquid. Now paint large streaks on the fabric.

You will achieve a better effect if your brush is almost but not quite dry.
To recreate a mold effect, make the whole costume, slightly damp and turn it inside out. Now dilute some white paint and paint it on the costume with an old paint brush. It has to be wet enough to penetrate through the fabric . Hang it up to dry. Wet a few patches on the costume with water and then dab on a dirty yellow color with a sponge to replicate mold.

Let it dry and then repeat the process. When you finally turn the costume the right way round, you should see a mottled blotch look.

If you like creating your own then you will find the above suggestions satisfying and good fun. You can, of course, experiment yourself with other colours and paints. If however you prefer to buy readymade costumes and save yourself  the  time, then a visit to www.officialpartydirectory.co.uk will show you the latest incarnations of costumes such as those worn by Johnny Depp in the pirate movies.