You will need to consider:
The size of the mattress
If you are lucky enough to already have a mattress which fits your body perfectly, buying a bed frame becomes considerably easier. If you have a double mattress, then you will want to buy a double bed frame. Similarly, if you have a queen sized mattress, then you will want to buy a queen-sized bed frame. If you have king-sized mattress things become a little more complicated because you will need to know whether you have an extra-sized king or a California king mattress. If you are re-doing your bedroom completely, then you will need to take into consideration, how much space you have in your bedroom as well as the size of the bed you will feel most comfortable with.
The size of your bedroom
Your bed is usually the biggest piece of furniture in any bedroom. If you have a large bed in a small bedroom, it can be especially overpowering. To determine whether you have the right sized mattress and bed for your bedroom, place the mattress on the floor of the room and take a step back. This was you will quite accurately be able to gauge the size of the bed compared to the size of the room.
If you feel that the bedroom is cramped, you will need to consider buying a smaller mattress before looking at buying a bed frame. In many cases, a bed frame will add extra length and height to your bedroom. But, if you have decided that you still want a bed frame, regardless of how cramped your bedroom will be then you might want to consider buying a metal bed frame as opposed to a large wooden bed frame.
The height of the bed
If you want to give your bedroom a more dramatic look and you have the space available, then you could always add height to your bed with the use of a four-poster or canopy bed. To effectively do this, you will need to aim your tape measure toward the ceiling. A tall bed frame requires a high ceiling. Even a large bedroom can start to feel cramped if you do not have enough ceiling space. You will also need to do careful measurements if you decide to get a bed with a bulky bedframe such as a sleigh bed or a bed frame-headboard combination with bookshelves included.
Your decorating style
Because the bed is the focal point of any bedroom, choosing the right style is paramount. If you want to create a warm, welcoming, comfortable feel, you may want to opt for a wooden bed frame, piling up quilts and pillows to set a cozy mood. Those who prefer a sleek, modern look should choose a bed frame of metal or wood with clean, minimalist lines. Once you've figured out what styles might fit in your bedroom, take a look at various models, including upholstered bed frames, sleigh beds, wrought-iron beds, and brass beds to find what suits you best.