>> Mini pumpkins. I've seen them at a handful of grocery stores for $.69/each, which is about as cheap as you can get as far as decor goes. They also last a long time, so you can have them around until you're ready to bust out the Christmas/Hanukkah goodies. (Once, in college, we had one last until spring. Magic!)
>> Candles. I'm a fan of the IKEA candles in glass votives, but any old black, orange, white, etc. version will do the trick. Bonus points if you bust out some old brass candlesticks for an extra creep factor.
>> Books. If you have any from the horror genre, or even a handful of hardcovers that are black, grouping them together is easy and free. I tend to do this more by color than by content, as you can probably guess since I have Jane Eyre in my collection.
>> Creepy artwork. Change out a few of your everyday pictures and see who notices. You can find printables on Pinterest, tear pages out of magazines, or check Etsy for ideas. My pictures came out of a Sherwin-Williams color preview for 2014 and have a mad scientist theme goin' on.
>> Black accessories. I use black details in my decor anyway, but I bring even more out this time of year. These lovebirds, for example, aren't very Halloween-y on their own, but combined with everything else around the house they add a darker feel.
Are you getting your Halloween on? What kind of spooky decor is your favorite? Raise your hand if you got the mini pumpkins at the grocery store!