This DIY [1] tree branch curtain rod project doesn't seem like most original idea ever. But actually, I've never seen it done before; it looks rustic-chic; it achieves that branches trend [2]; and it's super easy to pull off. Here are the steps, according to do-it-yourself [3]:

1. Find a tree branch slightly wider than your window trim.
2. Use pruning shears to remove long twigs, but leave a few stubs for character.
3. Spray-paint the branch or leave it natural.
4. Choose tie-top curtain panels, which allow you to adjust for the curves of the branch—no clips or rings needed.

Source [4]