You can make any sort of holiday-themed "grass" depending on the color of your bags. The liquor stores in Chicago tend to use black plastic bags; so those are perfect for this project. Step one, then, according to my boyfriend, is to go buy some beer.
NOTE: I do not recommend this project of people with animals that like to eat things off of floors or children that like the same. Please use your common sense.
Step 1: Gather your materials
1. Black or other appropriate color plastic bag
2. Scrap paper
It takes about 15 minutes to finish this project.
*You want sharp scissors for this. If it's been a while since you cleaned and sharpened your scissors, fold a piece of aluminum foil into eighths and cut through it multiple times with your scissors. Then clean the blades of with some rubbing alcohol. That should prepare them nicely.