I’ve put together a collection of decoration ideas for your Halloween party, haunted house, or to welcome trick-or-treaters. Sometimes a simple but clever idea can make a great impression, but the elaborate props you put your heart into will be remembered for a long time. All of these come with instructions.

Make your own Cylon Jack-o-Lantern. His eye is an LED that scans back and forth. You can alter the carving slightly to make an LED Dalek, Storm Trooper, or robot.

You don’t have to wear a Halloween costume to get use out of it. Instructables tells you how to build a quick, simple armature using PVC. Then you can make any kind of scary mannequin you like, using clothing and a Halloween mask!

Scary Terry designed a motion-activated moving skeleton with sound effects to scare passers-by, an effect he calls Skelevision.

The decorations only get more macabre, after the jump.

If old dried skeletons aren’t gory enough for you, you can make one into a Charred Corpse with some foam insulation and paint.

For an even fresher dead body, create your own Hollywood Gunshot Blood Effect (with video)! Just remember, if you are going to act out a fake murder scene, you might want to give the neighbors a heads-up before they call the SWAT team. See more DIY blood effects at the bottom of the instruction page.

Aranamuerta has a tutorial on how to create Witch Kitchen Jars, filled with such goodies as Snake Oil, Hob Goblin Brains, and Dragon Embryos. You’ll even get tips on making the antique gothic labels. These would be a nice kitchen accent year-round, if you are so inclined.

Take the jar idea one step further with a homemade Head in a Jar. This is a much simpler illusion than it looks!

Spooky Glowing Water is a simple but beautiful effect to use in a dark room. The main ingredient is a highlighter! A commenter at the instruction post used glowing water for a spooky fountain and left a picture.

How about a giant moving, spitting spider? The Spider Wiper is horrifying until you see how it works, then it’s cool! Instructions are at Village Haunts.

Printable Papercrafts may seem a little simplistic after the other projects here, but kids would have so much fun with these! It includes the creepy Moving Sculpture Illusion whose eyes seem to follow you around the room.

But if you have money to burn, a haunted house to furnish, and no time to do it yourself, go for the professional effects from The Scare Factory.

If you try any of these projects, be sure to take plenty of pictures or video. We’d love to read about the results on your website!