You will need a 12" wreath, which you can purchase, or make out of a pool noodle. I purchased mine at Hobby Lobby.
I usually do these type wreaths with grossgrain ribbon, which I prefer, but this one was made with a basic satin-style ribbon from Hobby Lobby. It was $4.99 for 30 feet of ribbon. It took two rolls of the black, and two rolls of the white to complete.
Simply cut your ribbon into 14" strips and begin tying. I tied my ribbon right over left, and then left over right - staying with the same technique throughout so the knots would appear the same size.
I chose to do four ribbons of black, then four of white, and repeat, all the way around the wreath.
The completed wreath is very simple - and it is a great base for other designs. For example, I can easily add clip on flowers to this, or a "boo" sign for Halloween, etc. The entire project took about 20 minutes, and cost under $15.00 (the ribbon and the noodle were both on sale the day I purchased them at Hobby Lobby.)