You have a number of options:
All fun patches and any other unofficial insignia should be placed on the back of the Girl Scout Cadette sash or vest. If you do not have room on your sash or vest, many girls have made patch blankets where they sew the fun patches on a blanket. Or some have sewn the fun patches on a sweatshirt or hoodie.
With a sewing machine.
The best way to attach then is by sewing them. There are various glues, including Badge Magic and other fabric glues such as Aleene's OK to wash glue that are easy and work well if you follow the instructions (particularly important for the Aleene's). However, the patches do drift some exposing he underlying glue (especially Badge Magic) and they are not easily removed. To remove them you need to use a solvent which damages the patch and leaves residue on the uniform. This is an issue as many people like to save the patches and the patches are sometimes updated and replaced. Also it leaves the uniform unfit for re-use by another scout. My tips: - There are several good videos on You Tube. - If the patch has a border put the needle under the strings of the border, not through the patch - it better preserves the patch and is much easier. - Hold the patch in place with hot glue before sewing. It holds position better than pins, is adjustable for a bit after application (before the glue cools) and peels off of the patch and uniform without leaving residue after patch removal. Some use double sided carpet tape. This works well but is not as adjustable. It will leave a residue unless you remove it after partially sewing your patch (apply it to the patch, sew half way around the patch, remove the tape, then finnish sewing the patch). - Get clear thread rather than trying to match all those different colors. I've heard of some using a fine fishing line but have not tried that. They do sell clear thread. The scouts make a kit with thread designed to match the insignia colors. It is expensive and does not do a very good job. You can get Badge Magic at the scout store or scoutstuff.org. You can get Aleene's or similar fabric glues at Walmart or most craft stores.
Put a boy in a girl scout unifrom
patches
Use a needle and thread.
is a place where we can put our sewing materials.
find a fabric store and buy some pieces of different colors of felt, cut them in shapes and put them on felt patches with fabric glue, or go to Hobby lobby, or Micheal's or a crafty place like that. There are even seamstresses that will embroider on the felt Patches.
To put a patch or patches on.
There are several suggestions of things you could do. 1) Sew the fun patches on the back so that they overlap. 2) Buy a vest because they hold more. 3) Get a patch blanket and sew the fun patches on the blanket, then you can sew the earned awards on the back of the sash if there isn't enough room for them on the front. 4) Buy a second sash. 5) Buy some matching material and add it to the sash. 6) If you have lots of fun patches, it might be fun to put them in a scrapbook with photos and memories of Girl Scout events.
A bobbin.
They go where ever your scout leader tells you to put them :P im a sea scout from Teralba NSW Australia :D