The first set I bought was a sheet of vinyl leaves for the hallway in our rented apartment, four dollars, and within a week half of them had curled up at the edges like old tape. The lesson that stuck with me was simple: the backing matters more than the design, and nobody tells you that until you're peeling a leaf off the wall with your fingernail at eleven at night.
When you're looking at a sheet in the shop, or when it shows up at your door, run your thumb across the back before you commit to anything. You want a matte, slightly textured finish, not something shiny and stiff that will show every bubble and crease once it's up. Check the wall it's going on too, because stickers that look fine on painted drywall can lift right off textured plaster or anything with a satin finish, and that's not the sticker's fault, that's a mismatch nobody mentioned. For rooms, I've had the best luck in spaces that don't take a beating, a nursery, a reading nook, the inside of a closet door, somewhere low traffic where nobody's leaning a shoulder against the wall every day. A kitchen backsplash or a kid's room near a doorknob is asking for trouble, grease and little hands peel edges fast. Humidity is the other thing nobody warns you about, a bathroom with no fan will have your stickers sliding down the tile by month three, I learned that one in our old apartment above a laundromat and I'm still annoyed about it.
Where they actually earn their spot is in a rental where you can't paint, or in a room you know you'll change your mind about in a year, a nursery that'll become a kid's room, a home office that might go back to being a guest room. Over time, decent vinyl holds its color and doesn't yellow the way the cheap stuff does, though any adhesive will weaken a little in direct sun, so a west facing wall will show fading before an interior one does. Cleaning is just a damp cloth, nothing abrasive, and if one corner starts to lift, a flat edge of a credit card and a careful press back down usually buys you another six months. When we moved out of that first apartment, the good ones came off clean, no paint pulled, no ghost outline, which is the whole point of buying this instead of wallpaper in the first place.
The one mistake I'd tell you to skip entirely: don't apply anything to a wall that's been freshly painted. Give it a full month to cure, or you'll pull the paint right off with the sticker, and then you're patching a wall instead of just peeling a leaf off it.