When decorating a girl's bedroom, you should consider the architecture of the home, the activities in the bedroom (sleeping, studying, reading, etc), and the preferences of the girl.
Decorating a shared girls bedroom is a bit more tricky since you need to accommodate the needs and wants of 2 or more girls.
Here are a few tips and tricks for how to decorate a shared girls bedroom.
Make it Special
Since the girls have to share a room instead of getting their own private room, spend a little more time and money decorating it to make it extra special.
Splurge on the unique furniture, the fancy pillows, the cute curtains, and the elegant accessories to make the room feel special.
Since two or more girls are having to share a closet, try to maximize storage wherever possible.
You can use a closet organizer to optimize the storage that you currently have.
Consider using furniture with built in storage, such as a bed with storage drawers underneath or a bench chair with storage inside.
You might even want to custom build a wall of beds with storage below to maximize the exact dimensions of the room and make it into a bunk room.
Instead of a standard night stand with little storage, use a small dresser instead.
Elevate the beds off the ground a bit so storage bins can be placed underneath to hold toys, games, or out of season clothes.
Also maximize the storage up high by adding storage shelves and tall cabinets to the girls' shared room.
Maximize Floor Space
Find ways to maximize the limited floor space.
Each girl can get a loft bed that allows extra floor space below.
Under the loft bed can be a lounge chair, a dresser, a play fort, and/or a desk.
Try to put larger pieces of furniture in other rooms, such as a dresser in a bathroom, wide hallway, or spare closet.
Identical or Similar
You may choose to decorate each side of the room identically, or you may choose to make the sides similar.
You can use bedding that is the exact same or you can use bedding that is the same pattern but in a different color. You might want to use a pink comforter on one bed with a purple bedskirt and on the other bed use a purple comforter with a pink bedskirt.
The girls can use the same colorful patterned comforter, but use different colored sheets, pillows, and blanket.
If you choose bedding that is similar with different colors, try to find something in the room that ties the two different colors together, such as a rug or large piece of art that has both colors.
If the girls have totally different interests and tastes, try to find a unifying element so the shared bedroom looks cohesive. If one girl likes black and owls while the other likes pink and unicorns, perhaps get a black and pink rug to tie the colors together. You can also get an owl and a unicorn sculpture and spray paint them both the same metallic gold so they coordinate. Add a few more metallic gold decorative elements for cohesion.
The larger the difference in age between the girls, the harder it tends to be to find common ground on decorating.
Whether the shared girls bedroom is for identical twins or siblings that are several years apart in age, each side of the room should have a bit of individualization.
You can decorate using a sign as artwork over each bed with their names, you can have a decorative pillow monogrammed with their initials, or you can give each girl a night stand or shelf to display their special trinkets, awards, and trophies.
Consider giving each girl their own pin board so they can display their special artwork, photos, movie tickets, notes from friends, reminders, and other scraps of paper that they find important or special.
Try to make the room special for each of the different individuals, not a room for 1 individual that happens to have 2 beds.
Separation and Privacy
Even though the girls are sharing a bedroom, each girl should have a portion of the room that is only theirs.
Typically single beds work better than bunk beds so the room can be visually divided in half and each girl stay on her own side.
If your girls want more privacy from each other, you can find ways to separate them from each other.
You can put a floor to ceiling curtain (or a curtain on a flag pole for separation in a certain part of the room), a screen, or a room divider bookcase across the room to create two different rooms.
If the girls have bunk beds, you can put a curtain around the opening of each bunk bed to block out the light and create more privacy.
Consider the activities that will need appropriate lighting in the shared bedroom.
Will one girl want to sleep while the other is reading?
Add multiple light sources in different locations to accommodate multiple activities.
Each girl might want a reading lamp by their bed that is not too bright to disturb the other girl(s) that might want to sleep.
If there is a dressing table where the girls apply makeup, the dressing table will need plenty of light.