Selecting your carpet for the living room or for the bedrooms you should have in mind the floor cover.There are different floor covers and each of them has its own typicals.Some of them do not allow to put a heavy persian carpet over.This is because of the traffic range and if it is high or low.You can discuss this with a floor or carper specialist.They can advice you which kind of floor/carpet to combine for your rooms.Color is important position too.But it depends on your choice to make a design of the room.It can be black and red,wood color and white carpet.Measurements are according the floor area too and the furniture.Try not to spread your carpet under the bedroom or chairs-their legs leave traces.Some people use to be multi precise and make special design combinations between colors,size and even pattern of their walls,floors and carpets.