DIY Halloween decor ideas :: Use a white stocking with stuffing inside and add more spiders to the bottom then around. You could also put a glow stick in a water balloon and have it look like they're surrounding a glowing egg sack.
DIY corpse in a body bag, made out of old clothes stuffed with grocery bags, styrofoam, and bubble wrap, then wrapped in white garbage bags and duct tape. Such an easy halloween prop. Hang it in a corner
"broken windows" : take frosted contact paper and cut it apart to look like fractured glass. The semi-transparent frosted contact paper takes on the appearance of the "glass" while the actual glass pane (which is transparent) disappears.
DIY your own spider trail with plastic spider rings.