Who are you and how does your home get used? This is an important part of the process because the answers to those questions will determine where you should begin decorating your home.
I have heard designers and decorators say the first room you should always decorate is your master bedroom. The theory is you are in this room the most and therefore it should be a well centred, organized place. If you wake and sleep in a beautiful place, you will be happier.
My argument is that I am awake more in the lounge or kitchen than I am in my bedroom and I like my public spaces (kitchen, family room, living room, and dining room) to appear pulled together first. This, of course, is based on my lifestyle. What is YOUR lifestyle?
If you are a person who loves to entertain formally, then you should consider working first on your living room and dining room, if you like to entertain informally with friends and family, work on your family room and kitchen spaces, if you are a cook and everyone congregates to your kitchen, then by all means finish that room first. If you are a homebody and just love relaxing in your bedroom, complete that room first. If you are a busy professional and are rarely home, then the bedroom theory from above may be the best for you. Typically, you will be in that room more often anyway.
Once you define what areas are most important to have completed first, you will be well on your way to a finished home. The answer to the question, "what rooms are most important to be finished first," can not be all the rooms! If you set yourself up for that kind of overwhelm, you will not be able to accomplish anything.
If you don't focus on what area first, second and third, you will become very overwhelmed by all the things you need to accomplish. Why do that to yourself? Break it down into smaller pieces and get it done.
Figure out with your lifestyle what rooms are most important to finish first while keeping an overall eye on your whole house. If you see bedding that would work for your master bedroom and it's on sale, go ahead and purchase it, but don't then switch focus to that room when you are almost finished with the family room. Once you find your style, the rest falls into place.
Modern is probably the most popular style among young professionals. These working men and women don't want to worry about dusting small grooves of more ornate designs nor do they want to mess with a bunch of knickknacks sitting everywhere. Clutter and chaos are out; straight lines and organization are in.