You don't have to spend a fortune to hang curtains. Be the first on your block to bring Office Supply Chic to your home. All you need is push pins or nails to secure small binder clips to the top of your window. It's best if your fabric is wider than the window. Gather it to make small drapes along the top. Experiment. So easy to change.
Use a second set of binder clips to tie back the curtains. You can drape them, as above, or bunch them, or whatever you like. I've used very sheer white fabric here for summer. But come Winter...I've got some very nice flannel buffalo plaid fabric to use. Wait and see.
Meanwhile, get binding!