How do I decorate a room without making it look cluttered??

Rule of 3 for arranging items.

Follow the jewelry rule: When you think you are done, remove a piece.

Perhaps find an inspiration photo and mimic it.

Make sure you can still see supporting pieces (shelves, sofa, bookcase, etc) well enough to identify shape and bones.

Recruit a buddy you can trust for an honest opinion, aka not your significant other.

Isolate to one curated area. I like to put things on this shelf and stack them like the plant on top of the jewelry box.

Do you have a friend who's decorative style you admire? Ask them to help you out. Prepare by removing all your decor and holding it in a "staging area".

First, show your friend your most loved items so you can showcase those. Fill in by creating themes, collections or colors.

Hold on to some favorites that you can rotate and keep your decor fresh. Don't feel guilty about donating stuff that isn't "worthy".

Take your friend to lunch or dinner, (their choice), as a thank you.

Every season I pull everything out of my spaces and slowly add back those items I love. It feels fresher and I don't over collect.

clutter comes from shelves, tabletops, islands, end tables, and coffee tables having too much on them. I think people immediately think clutter when they see that. Try to minimize what you put on top of those areas and I think you will feel better immediately with that one trick. The next trick is letting go of stuff that is not needed! HMM...one of my biggest problems! Good luck.