A while ago I got an e-mail from Rachel. She and her husband are moving cross country to live in their first place. She wants to get some advice on how to start out setting up their first home without bringing the hodgepodge items from their college days.
I can only tell you how I would go about it if I were to start out. Feel free to share your advice for Rachel and others starting out in the comments.
The rooms themselves
When you move in, keep it neutral. If you're renting, maybe the renters white isn't such a bad thing. If it's your own place still keept it neutral to begin with until you've gotten the feel for the place and seen how the light falls, which room is dark, which one might need a bright lick of color etc. If you're living in a small space like we do, keep the color or colors consistent throughout.
In our small house it means we have the same or very similar wall color on all walls and the two walls which are painted in a different color, one in the livingroom and one in the bedroom work well together. What this does is make the different spaces flow into each other instead of startling you in each new area. If possible keep the floors unified too and the ceilings. This will make your space feel larger. If you are renting and desperately want wallpaper somewhere one idea is to get a large board and wallpaper that and simply lean it against the wall where you want it. Like behind the sofa or desk.
You spend about a third of your life in bed so get a comforable one. It doesn't have to be expensive. Ikea make pretty good beds and there's a wide selection to choose from to get the right one for your weight and sleeping preferences.
If you like wood, choose one type and be consistent in using the same throughout. So if you like oak, stick to oak throughout instead of going for oak on one piece of furniture and beech the next. This will also make for a more unified space.
When choosing a sofa and armchairs go for a neutral color on those as well. I'm starting to sound like a broken record. When you are just starting out together you might not have found your "couple style" yet. Neural background will allow you to perk things up with pillows and throws and will let you experiment with color and texture without spending a fortune. Martin and I are not starting out, we've been together for over twenty years but this is still how we do it. I love changing the mood in our home by simply changing a few pillow cases on our white sofa. Neutral don't have to be white though if you are afraid of it getting dirty. Beiges, greys and browns are other great neurals which will allow you to switch accent colors freely.
When you have the big heavy (and more costly) pieces down you can then add tables, chairs and occasional tables. I would suggest you get a good sized table which can do double duty. I love to mix vintage and new here, so you might consider getting a great new table where you can eat and which doubles as a desk or craft area and then get a set or a mix of vintage chairs to go around it. A vintage coffee table will give character to your storebought sofa if you like that kind of a mix.
Good storage for me is key to keeping a neat house. I like to get a lot of the same color and style of boxes and other storage pieces. This again helps keeping everything unified. If you get two pink boxes, two blue and two green ones your eyes will be drawn to the boxes and in my mind storage is a thing for the background, not to be focused on visually. I prefer to see my art and my chosen objects instead of the boxes with the rest of my nick nacks.
Again Ikea is a good source for storage, both for boxes and larger pieces like book cases. My favourite bookcase from Ikea is Expedit which can be fitted with different types of drawers which are useful for the not so pretty things which you still want accessible.
One version of the mantelpiece...
...and another version of the same spot.
Once your furnishings are in place and your stuff is stored the fun begins! Soft furnishings, art, objects and flowers. If you have the neutral background you can probably go a little crazy now adding the colors of your choice. I'd recommend you to keep it quite simple though. You don't need to display all your objects at once. Choose a few and store the rest. Bring items out from storage every now and then and put some of the ones that were displayed in storage instead. I love doing this, I change the mood by switching a couple of pillows and a few nick nacks and it's like mini makeover.
I hope this helps! Good luck on the big move!