Just some other food for thinking on, my theme that I use every year is a cemetery.
I use many headstones that I have done up myself
Three coffins, one I have made and can support a human actor. Possible 2 coffins can be used for actors, but the one is cardboard
I incorperate the use of 3 foggers on is a ground fogger
2 Strobe lights and one red or blue flahing light
3 stand alone monsters (not live- but could be) just need actors to do the trick. I have three other costumes to use for actors so I have enough for 6 monsters
Lots of multi colored rope lights and extension cords
I also use many small props like spiders and webbing.
Last year was my best year I was able to use my cemetery wall collums and had flashing pumpkin heads on them.
It was also my first year in a little while not doing any live actors, but I rigged up a costume on a tall standing fan that turned back and forth and the kids love that one, they could not figure out how it works, but it was SO SIMPLE!
I know all the kids look forward to what I do every year and I only do it on Halloween. I have been doing this for about 8 years now and dont plan on stopping. I add a little more each year on a budget, so it has a new look.