When decorating rooms it's important not to think of them as a single entity. Every room should connect to those around it in some way. If they don't you end up with a very choppy looking and disjointed home. Don't worry though, when decorating rooms it's easy to make them connect and flow together.
An easy way to make rooms connect to each other is with color. Some people like to paint their whole home in a single color and then decorate and accent with other colors. This is an option, but it's far from the only one.
Choose a color that will carry through the home. It doesn't need to be the primary color in each room but it should make some kind of appearance. It can appear in the form of paint, fabric, accessories or anything else you can come up with. If you're going to be using it in accessories such as pillows and decorative accents, use it more than once and use more than one shade. A single vase won't cut it. Use it a few places in the room in various shades and tones to create layers and depth.
If you're going to be painting rooms different colors try not to use too many. Try to choose four to six colors to use throughout the home and stick with them, otherwise it can be a bit dizzying. If you live in a small home try not to use more than four. This might not sound like a lot but if you use too many your home will start to look cluttered and complicated.
Important tip: When decorating rooms and painting them different colors paint the trim all one color. It's an easy way to make the rooms connect to each other.
A great way to make rooms flow together is with style. Choose a style you love and use it throughout your living space. Just don't make every room a cookie-cutter version of the one before it. Use different colors, materials, and furniture shapes to give it some life and vitality.
Eclectic decorating is wonderful, but it's important to make rooms eclectic – not the home. By this I mean that you should not decorate one room in a particular style (such as French country) and another room in another style (such as Shabby Chic). If each room is done in a different style the home will be a confused mess. Instead, if you really love different styles and want to incorporate them all, use elements of each in each room. It's not necessarily an easy task, but it will make the rooms flow together in a far more effective way.
Sometimes people are drawn to a particular material. If this is the case you can repeat it throughout your home as a common thread. As a personal example, I'm very fond of vintage French and Italian Gilt. I have gilt sconces and a chandelier in one room, gilt lamps in another, and a gilt mirror in yet another. All of them in one room would be too much, but dotted throughout my home they work quite nicely and create a nice connection.
In a small space it's always nice for the flooring to be the same in every room. It's not as necessary in a large home, but in smaller ones try to keep the flooring consistent. For example, the same hardwood floor running throughout the home will prevent rooms from looking disconnected. You can add interest and color with area rugs and runners – as long as the base flooring is the same throughout it will work.
If the flooring is different and there's nothing you can do about it you can try to create a connection by using area rugs and runners that are the same color or material (such as sisal or jute).
If the floors are drastically different from each other and area rugs aren't an option you might want to consider painting the rooms the same color. It will soothe the different floors and create some sense of flow.
The most important tip when decorating rooms is to decorate with items you really love. I always maintain that if you stick to your own style and choose items you're really drawn to they will somehow all work together.