Placement of insignia on the uniform is important.
The Uniform Inspection Sheet has insignia placement guides.
There is also a Male & Female Leader Uniform Inspection Sheet.

If you wonder where a patch goes, it is probably a 'temporary' patch. They can be displayed on a blanket, vest, wall display, shoebox, or the back of the merit badge sash.

See the BSA Insignia Guide for more information on uniforms, patches, and such.

The Scouting program in America has always included uniforms for its members and volunteers to identify members and show they are part of the Boy Scouts of America. Scouts and leaders should wear their uniforms to all patrol meetings, troop meetings, and scout outings.

The tan and green Boy Scout uniform is a well-known symbol of American scouting. All scouts in the program wear the same uniform with the major differences being the badges each scout has earned and the troop specific neckerchief.

Most scout troops also have an activity uniform which is often a t-shirt customized just for the troop. Activity uniforms are worn for work projects, sporting activities, and other events in which the dress uniform might get damaged. The official dress uniform is commonly referred to as the 'Class A' uniform and the activity uniform as 'Class B' even though these are not correct BSA terms.

Each scout belongs to a patrol within the troop. To foster patrol identity, each patrol chooses a Patrol Patch and creates a patrol flag, name, and yell.

Sashes and Such
The BSA Insignia Guide discusses all the uniforming, patch placement, and other insignia use.
Merit badge placement on the sash is up to the scout. The badges can be displayed in rows of two or three, starting three inches down from the top of the sash.
There is no required ordering of badges. The scout can put all silver-bordered Eagle-required badges first, followed by green-bordered elective badges. Or, he can display them alphabetically, or by favorites, or by color, or in the order earned (which is most common).
When the front of the sash is full, additional merit badges can be displayed on the back or on a second or third sash.

The merit badge sash is worn draped over the right shoulder and left hip.
Only ONE sash is worn at a time.  A second sash is NOT worn over the shoulder, nor tucked into the belt.
The same is true for Order of the Arrow sashes. The scout wears either a merit badge sash OR OA sash, but not more than one sash at a time.