My idea and your idea of the perfect bedroom are probably different. The bedroom is such a personal room that the perfect version can be anything you want it to be. But whatever idea you have in your mind about your perfect bedroom, there is bound to be a bedding ensemble to suit.
Bedding ensembles are sets of different bedding items put together by a designer so that each piece works well with every other piece. The sheets are the perfect color to tone with the comforter. The bedding skirt matches the sheets. The bedding cover (whether comforter or duvet cover) goes with everything. There might also be decorative pillows included in the collection in different fabrics but each fabric is designed to coordinate with all the other items.
You can find bedding ensembles which are sold as a whole collection (a bed in a bag) and you also find those where you choose the individual pieces to make up your perfect bed.
As the bed is the focal point in a bedroom it is important to get the bedding just right. Buying a well-designed set of coordinated bedding in the form of a bedding ensemble allows you to do that more easily than you could if you had to shop around for individual items.
By starting with great bedding that you know is well coordinated you have the ideal starting point for decorating the rest of your bedroom. Simply match up the colors of other items for your room with those within the ensemble. For example, if you have chosen a bedding ensemble with a green and blue floral design on a cream background, choose the cream color for the walls, and cream, green or blue for the curtains. Then pick out a few accessories (perhaps a bedside rug or bedroom chair) in the exact same green or blue color.