In our local area, buying styrofoam tombstones costs around $25. Now many DIY methods of making tombstones involve buying plywood and cutting it with power tools, but my method is simple enough that no power tools are needed. As far as budget goes, we spent $50 and make six good size tombstones.
In the hardware store find stryofoam insulation sheets. The sheet we got made six tombstones, and I am assuming it was a standard size. Ours was a blue sheet of styrofoam, but I think they come in pink as well. If you are limited in the size of your vehicle, then most hardware stores will cut it in half for free if you ask. You will need a carpenter knife to cut the stryofoam at home, so if you do not have one then pick one up at the hardware store. You will also need spray paint: two cans of a gray primer and 3 cans of rock textured spray paint (we got black granite color). You will also need yard stakes and zip ties to secure the signs. So here is the shopping list:
Sheet of stryofoam insulation (blue or pink)
2 cans gray primer spray paint
3 cans rock textured spray paint
1 can black spray paint.
carpenter knife (if you don't have one already)
12 Wooden stakes (like for yard sale signs)
24 Zip ties
Now you can go home and cut out the sheet of stryofoam into 6 equal sizes. You can now look for various design ideas or simply make a curved top. Trace everything out with a pen or pencil first and then cut with and x-acto knife. Peel off any plastic that maybe on the stryofoam insulation.
Spray paint the cut out tombstones with the primer. This helps the textured spray paint stick and greatly reduces how much textured spray paint you will use, which is important because it is more expensive. The primer dries fast, so once you finish the first grave will probably be dry enough to spray the textured paint. This paint takes longer to dry and may require a second coat.
While you wait for the paint to dry. Type up on your computer, using a word processing software, what you want to say on your gravestone. This is where you can get creative or just look up sayings off the internet. Select a font that would look alright as a stencil. Select a large font and print off the saying, try and use one page for each gravestone and remember you can use landscape view if you have a long saying. Take the x-acto knife and cut out the sayings.
Once the gravestones are dry, secure the wooden stakes to the tombstone with the zip ties. To do this, simply poke a hole large enough to thread the zip tie through. We used two stakes on each gravestone with two zip ties holding each stake. Secure them tight, but not too tight because you should be able to move the stakes which makes storage easier.
Using thumb tacks or tape, secure the stencil on the tombstone and spray the black spray paint over the stencil. Wait until the paint dries before removing the stencil. With some luck, we have found that some black spray paints use a chemical that eats away at the stryofoam which gives a cool engraved look.
Now just place them in the yard on Halloween night and enjoy the chuckles as people read your funny and unique tombstone sayings such as: Poor Kelly Drowned in Jelly.