Righto what do you do with old Halloween signs? Reinvent them... I got mine originally from Asda for a £1 - which is a bargain for thin mdf! You can find a link to their site here http://www.asda.com/halloween.
Step 1: Upcycle Your Old Sign With Paint
First of all give the signs a quick sand as it removes any raised text. Next paint - it doesn't matter what you use providing it's permanent so use acrylic, spray paint or blackboard paint as it will stick best. Leave it to dry and do that outside if your paint has fumes - obviously.
Step 2: Vinyl
So I used a Silhouette Cameo vinyl cutter but you could do this by hand or with stick on letters for the intricate cuts. It also doesn't matter what colour vinyl as we'll be removing this later. You need to weed out the letters from the backing piece but it also means you have the negative for another sign. At this point I'd advise you use transfer tape to apply the vinyl but I was feeling lazy so just placed them directly on the sign bit by bit.
In the pics there are lots of colour of vinyl which is because I made a few and messed a couple up as the blade was blunt.
Step 3: Trace the Design
For the next part all I did was spray the sign lightly with white so that I had a lighter background on to white to apply paint it also gives a primer even coat. The next step was to follow that up with acrylic paints in lots of rusty or old signage colours for texture and interest.
Step 4: Painting the Detail
Next remove all the vinyl which will leave the black behind and give you a background into which you can add detail or even leave it black. I wanted it to look more like a worn sign so I painted over the black with a mixture of acrylic in bloody tones.
Step 5: That's It...
Just let it dry and then hang it up!