If you want to provide some sort of privacy with glass front doors, but don't want to stand out like a sore thumb, there are a few different options to choose from. Consider the tips below.
Tint the Glass
Just like you can tint your car windows, you can tint your glass front door. This can be done by simply purchasing some glass tint at a local home improvement shop or auto shop. Follow the instructions on the tint carefully, and be sure to smooth out the wrinkles. Choose the grade of tint that will provide you with your desired privacy level (found in the visibility measure of the tint).
Add Opaque Window Coverings
You can choose to go with a frosted-over look that will be similar to the fogged glass found on shower doors. This, again, can be purchased at a home improvement store. This look works well for glass doors made up of a lot of small rectangles because you can fill them one by one.
If you want to go for curtains, try using a sheer and a heavy curtain. The sheer will be similar to the frosted treatment mentioned above in terms of coverage, and the curtain itself will help add an actual design element to the mix. Pull back the curtains to showcase the door at its finest.