Right now I am in the middle of a very fun project in Boston's South End for a family who just moved back after spending two years living in Paris. In the oldest boy's room* (they have three little guys) I'm having a french flag framed, similar to what I did in our boys' room, as a nod to the years he spent living abroad. I've said it before and I will say it again, using a flag as home decor is such a great and inexpensive way to bring color and life into your home! You can get the look of large scale art, which usually is very pricy, for next to nothing depending on the flag you choose. We chose a Swiss flag in the boy's room to bring some of my husband's Swiss heritage in to our home but even if you don't have an international affiliation, a flag from your home country or a vintage flag from a flea market can add just as much personality to any space.
I usually have the flags frames and matted (I do all my framing at Blick art because they always have 40-50 % off sales) usually because I'm buying less expensive ones that aren't always perfectly rectangular. However, I have to say that I love a flag pinned up (or even as curtains- see below) just as much as I do one framed. It really depends on the flag and the space. One can read more eclectic while the other feels more like an art piece- it's really all about budget and personal preference.
The key when framing a flag is to make sure you have all the wrinkles out. I usually just order my flags from amazon, so they typically come folded. I use a mini steamer (never use an iron it because often the colors will bleed) and I try to get as many of the wrinkles out as I initially can. I then hang the flag near the shower for a few days to let the rest of the wrinkles naturally fall out, giving it another good steam and ROLLING it around a tube when transporting it to the framer. When framing you really want to make sure they will sew it down under the mat, that way you can get a tight and wrinkle free finish. If you are just hanging it, one good steam should do the trick as the wrinkles in the cotton are definitely part of the look. (If hanging I would make sure to buy a cotton vs nylon flag.)
Below I've pulled a few of my favorite spaces that use a flag as decor. As you can see the options are endless and the best part is when you tire of it, you can always switch it out!
*note- when using any large scale art in a kid's room I always have it framed in plexiglass just in case it ever falls off the wall. With kids you never know what could happen, better safe than sorry!