Never, ever do a room from any one store. Certainly not an entire house. It looks peculiar.

Ecclectic is nice if it does not look cluttered, there are ways to do it properly. The highest end homes usually do not have "matchy, matchy" - if you don't believe me, have a look for yourself.

You have to look at the room and have a "vision" - it is not something that is automatic, a given, nor can someone accomplish it without seeing the space in person.

It is part math, part art, part talent.

09:52 here.
Just read some other posts and wanted to comment. I mentioned the importance of window treatments and they are very important. Plantation shutters or silhouette blinds are classics. Cheap curtains from Bed Bath and Beyond will always look cheap (I have them in my walk out basement because I liked them and didn't want to spend a lot. They match well and are nice but nobody is going to think that room looks fabulous and it's mostly because of the window treatment!)

Also - there is a formula for how to use color in a room. The person who said you can add a blue and coral throw to a room with three other colors already must have a bright and busy home. It's hard to have a rule but this seems like a lot to me. Pick two neutrals and add a non neutral for fun. Four or more colors is a tricky thing to pull off so if you aren't sure - just stick to three right now)

Lots of decorators say every room needs a little black. I think it can be true but of course there are exceptions.

Also try a few plants but not too many. A large plant or tree inside fills space or corners and adds a little "life" to the room.

Also - if you have orange wood floors - have them refinished. It will completely change your home. Orange wood is really dated and it's hard to move past it in my opinion unless you have some good rugs (oh and I'd skip the oriental carpets - especially the fake ones. Unless they are pricey and you want a traditional look - oriental carpets aren't a great look)

It's hard to just give general advice. My mom was a great at decorating our home (self taught) and I think it was just in my blood. I never understood how people could be comfortable just putting in any old sofa and and old side table and leaving it like that. For me, I need the right window treatments, rugs and furniture. Never matchy, matchy but always coordinated in some way.

The one quick rule is when selecting paint - start with grays and work your way out. If you want blue - go to gray swatches and move out until you get to a blue.

This doesn't work with yellow or every color but it is a good rule. I have friends in expensive Bethesda homes with neon blue or green paint and it looks just awful. It took them months to pick it out and they just didn't know where to start.

Buy neutral sofas (never ultrasuede. If you need durable - do leather. I have leather even though I don't love it. Kids destroy upholstery though. Hate slipcovers unless they are super high end. They just look messy.)

Never do a room all Ikea. Two or three Ikea pieces in a home (esp kid's rooms) is fine. Anchor a prominent spot in your home with built ins or an expensive piece of furniture. Things flow from there. You should have a focal point in every room though. If there isn't one thing you are proud of in each room, fix that.

Make sure you have enough storage. Clutter makes any space look awful. I have a tiny pile of mail I'm working on in a tray. Otherwise, everything gets put away. Every day. I have an island in the kitchen with a fruit bowl. By the end of the day, it is a mess. I do not go to sleep until it is cleared off.

Do a LOT of research. It becomes an addiction.
Google photos of the paint colors you like so you see them in a real room. Get some magazines. Just stay away from super trendy things. By the time you see them, trust me - it's over.

Have fun.