Girl Scout Fun Patches (unearned patches, usually purchased as a souvenir of an event or troop activity) go on the back of the sash or vest. Some Girl Scouts put them on a Patch blanket.
Girl Scouts of the USA earned Awards and Official Insignia go on the front of the sash or vest and there are specific places for them. See Related Links for a link to the GSUSA web site which shows where the various Awards and Insignia are placed.
It depends on the Girl Guide Association you are asking about and maybe the level.
Girl Guides Australia have specific places for each badge/insignia.
Girl Guides of Canada also have specific places and the information can be found in the girl's program book.
Girl Guides of the UK are pretty much allowed to places the badges where ever they want with the exception of a few specific places for some insignia.
For Girl Scouts of the USA (GSUSA), earned badges are placed at the bottom of the front of the vest on both sides and at the bottom and on the back of the sash. Some specific badges have specific placement.
Check out the guide for placing insignia on Girl Scout uniforms.
Girl Scouts "earn" "badges" but "collect" "fun patches."
The Girl Scout Give Back patch is an earned badge so it goes on the front of the vest or sash, near the bottom, where the other earned badges are placed.
All earned awards for Girl Scouts should be worn on the front of the vest. For more information, please visit girlscouts.org/en/our-program/uniforms/where-to-place.html
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.
The Bridge to Cadette Girl Scout Award is placed directly under the Brownie Wings on a Cadette sash or vest.
In the USA, Girl Scout Cadettes, Seniors, and Ambassadors all wear a tan vest. See related links to see what a Cadette/Senior/Ambassador vest looks like.
One the Cadette Girl Scout vest, the Bronze Award pin is worn to the right of the insignia tab. On the Cadette Girl Scout Sash, the Bronze Award pin is worn to the left of the Troop Numerals.
The "You Are Registered" patch is not an official Girl Scout insignia, so it goes on the back of the sash or vest.
When Girl Scout Cadettes are participating in a ceremony or officially representing Girl Scouting, they should wear either the Cadette/Senior/Ambassador tan vest or tan sash for the display of official pins and awards. The unifying look includes a solid white shirt and either khaki pants or skirt worn with the vest or sash.
The charm holder pin goes on the vest on the girl's right, under the "Bridge to" Award patches. Note: the STUDIO2B program has been discontinued, however, if a Girl Scout earned any charms, she may still wear them on her vest or sash.
For Girl Scouts of the USA (GSUSA), the earned badges go on the front of the vest, underneath any other earned insignia. It is a good idea to start attaching the badges at the bottom of the vest. Any fun patches received go on the back of the vest. Other Girl Guide and Girl Scout organizations may have different guidelines for badge placement.
Normally, you transfer the ones that you don't earn, like the Flag, the troop numbers, the Brownie Wings, and any special patches you bought at the store. (You don't have to take these off if you don't want to. You can buy new ones at the store.) And don't forget the Bronze award pin if you earned your Bronze award. It all usually depends on what you want on your vest. If you want your favorite patch, say, the Theater patch, on your vest/sash, go for it. But you can't earn badges as a cadette. You earn IP's, but you probably already knew that.
All fun patches go on the back of the tunic/vest/sash. Only official earned insignia goes on the front.
The Girl Scout sash is designed to lay on the right shoulder, go around the body, with the bottom of the sash on the left side of the body. The Girl Scout vest is designed so that it is worn by inserting both arms with an opening on the front. Placement of the insignia and awards is different on each. When wearing the Girl Scout sash, the pin tab with the membership pin and the WAGGGS pin is worn on the left side of the shirt rather than being on the sash. See related links for illustrations of both the Girl Scout sash and the Girl Scout vest.
The Early Bird patch is not an official Girl Scout insignia, so it should be placed on the back of the Girl Scout sash or vest.