Take small styrofoam balls and white napkins. Open up the napkin, place ball in the middle. Cover ball with napkin and wrap white or clear fishing line around it. Fluff out the rest of the napkin, take a sharpie, make eyes, nose and a mouth. Instant ghosts. Hang them up inside windows facing the front yard. You can also tie them onto a larger string to frame the window with them.
It's not hard to create something that moves when the door opens. Take a small hook, hang it above the door. Take the thing you want to hang, attach a long piece of string to the thing, loop it over the hook and attach to the door. When the door opens it should lower.
You can find large pumpkin trash bags, fill them with leaves or newspaper (depending on where you live). They are really cute in the front yard. If you have a spot you can even hang ghosts so they are floating right above the pumpkin.