I would totally do signs at the popular corners to direct more foot traffic in your direction. I personally would not consider a cool sign with an alert to go check out a really nifty haunt with amazing spooky stuff and FULL SIZE CANDY BARS as tacky but even if one did, goodness, if you can't be a little tacky on Halloween, then when can you?
I've seen several haunters make really nice looking and professional LARGE vinyl signs that can be put up at the head of the street/neighborhoods (in the medians) advertising their haunts. One of the really good sources is Shindigz and
Ghost of Spookie (you may want to follow them) is a lovely/awesome HF member here that posts when they see the discounts/sales for sites like this. Like this one (pretty sure it's over with, but you can see the stuff and samples of what they put on sale and the location of the discount announcements on our forum):
Shindigz and sister company Stumps Party have a 25% off sitewide sale going on now thru tomorrow, Monday, 12/14 @ 7:59 pm PST (kind of weird cut off time). I think 25% off is maybe the best discount offer they put up except on clearance items occasionally. Shindigz online code 25DECSZ...
www.halloweenforum.com
For any of the actual signs, I'd check with the neighborhood/houses that are near where you'd like to put them up and ask them if it's okay so it doesn't get thrown out (some counties and even neighborhoods have rules regarding advertising signage so you'll want to get it cleared up before). Make sure to put up a week or so before the big day so you get as many eyes on it as possible!
Also suggest looking at your neighborhood Nextdoor as they do a Trick or Treat map every year and you can also post in the main feed about your haunt so your neighbors can see details (Nextdoor does allow you to restrict posts to your neighborhood only, or to nearby neighborhoods as well). Same with any Facebook groups, and if you have a neighborhood newsletter or website, ask to put an ad in there or write an article to submit for posting.
If you have kids at the local elementary or middle schools, send a flyer or ask the school to post it on their school site. If you get a good deal on vinyl signs you may even want to see if you
could put up one right across from the local elementary/middle schools (especially if it's near the car rider entrance/exit so the parents can see it too).
Using social media or advertising at the schools may be a bit of a mixed bag; you may just see a small increase, but you could also risk going viral and ending up with a disruptive/damaging swarm... so I'd weigh the idea with the amount of kids/traffic in your area and decide how comfortable you are with handling REALLY large crowds and have some safety measures in place if you go that route.