With flag manufacturers designing and making flags on just about any subject in the world there's a good chance you will be able to buy the type of flag you are looking for. But if it's something unique or personal you want you may have to custom design your own flag. You can either design the flag and have a flag maker produce it for you or make the whole thing from scratch by yourself.
Making your own indoor, outdoor or car flag is simple really; all you need is a piece of fabric of any color and a pole or stick to fly it on. You can add your own design, words, photo or emblem by drawing or painting on the fabric or ironing or sewing on your logo. Flags are usually rectangular in shape, but you can make one of any shape and size as long as it's practical for flying, and although it is uncommon, you may also make your flag with designs on both sides of it. People may want to make their own flag to convey a personal message, such as a marriage proposal or to give as a gift. You can make a flag with a photo of yourself, your family or your pet on it or an occasion such as a wedding or birthday.
If you'd like somebody else to make your flag there are many companies to who make custom flags. You can even design and send your artwork to companies via the internet and they will offer you suggestions and help with your design. These custom flag companies allow you to use any colors and logos and will make just a single flag for you or can mass produce thousands.
People who use custom flags and have them mass produced often include advertisers, cities and towns, real estate developers, resorts and Chambers of Commerce since custom flags are excellent marketing tools to promote your business. People have been using flags for this purpose for over a hundred years. Some companies have pre-made designs and you can just add your custom flag message or logo to the one you like or you can design the whole flag by yourself.
Remember if you are going to fly your custom flag in public it shouldn't be designed to offend anybody.