They say two minds are better than one, and when it comes to planning, prop making, and decorating, this statement is very true. Plus, some people have access to certain items you might not know about. For example, one year a friend of a friend was happy to let us park his old hearse outside our haunted graveyard!
You can have all the special lighting, eerie sounds, and amazing props in the world, but the most successful and scariest haunted house features are real, live people! Recruit people to dress up in costume and become a part of your haunted house. No special skills or acting abilities are needed. One of the scariest effects is to simply have costumed 'actors' stand or sit motionless in amongst your props and dummies.
The 'actors' don't have to move or jump out at people for the best results. Try to blend in with any dummies you have stuffed and lying around. Visitors won't know what is real and not real. Making just slight moves also works well. Take a step when the person's back is turned or change positions a little bit. Slowly sneak up behind them. Don't touch them; just stand close. Hide behind black sheets, spider webs, coffins, tombstones, etc. People who visit your haunted house will succeed in scaring themselves just by wondering which creature will move next.
Don't be afraid to ask your friends, families, and neighbors for help. It makes life a lot easier for you, and it will also help to make your haunted house much more successful! We always have at least a dozen people helping us. Everyone always has a blast and comes back for more the next year!