My bathroom has two permanent-marker details: the walls and the mirror. There is nothing cheaper and easier than taking a large ruler and pretty colored Sharpie to create simple fine lines on your wall. The mirror was pretty before, but I adore the extra delicate gold detail over the mint-color cutouts on the mirror frame. You can read more at Cuckoo4Design.
You don't have the money to spend on expensive wallpaper? Then take a look at this tutorial here that was inspired by a beautiful designer wallpaper. And if you don't want to put in the time to give an entire wall this permanent-marker treatment, then try it on a small piece of furniture, which would be the perfect way to give it some chic detail on a budget.
This pretty plate comes from an easy idea -- just add detail with permanent marker -- that you could even do with your children. I certainly love it as an adult, and I love that you don't have to get really ornate to make a sweet statement. Amy of Delineate Your Dwelling shows how to make a simple heart, which isn't just suitable for Valentine's Day.
Sharpie wall treatments are everywhere on Pinterest, but what makes this accent wall different is the unexpected quirky black sheep among all the white outlined sheep. I love this little detail that some people might not even notice because it is subtle. I could also picture it in a fun kid room or nursery on a larger scale. You can find out all the details from Cassie at Primitive and Proper.