I've been making a Christmas wreath for our front door for years now. It's easy and can be basically free too. Free is always good. The only necessary expense is some florist's wire. I bought some back when my oldest child was in hippie German pre-school. He's in eighth grade now. I've nowhere near used it up. Green wire would be better, but I bought this for something completely different and since I have it, I use it.
One also needs a frame. For several years, I used a wire coat hanger as a frame. Just pull it into a circle, pinch the hanging part tight and you have a loop to hang the wreath from. A few years ago, I realized I had an old fake wreath I didn't want to use. I pulled the stuff off of it and now I use that as my wreath frame.
Then you can add some decorations. This year I went with a few pine cones, I've picked up and saved and some bay leaves from the giant bag I bought at the Indian grocery store and haven't used up. I just wrapped the wire around the pine cone, used a hole punch to make a hole in the bay leaves and wired it to the wreath.
And when it is done to your satisfaction. Hang on the door.