Another DIY headboard option? Wood, says Michelle Harrison, an interior designer in San Diego. Wood slabs are relatively inexpensive - you can buy them on Etsy - and easy to install.
Another alternative: Peel and stick wood like Stikwood, which you can literally stick on the wall.
Instead of painting one monochromatic color, divide whatever you're painting geometrically - into triangles, rectangles, whatever - and play around with two or more colors, says Harrison.
A pop graphic print - even if it's just on a throw pillow is a super simple way to make a style statement, especially when you want to maintain a relatively neutral palette in the rest of your house, says Harrison.