I get this question a lot “How do I find the right lamp for my room?” First consider your family’s lifestyle and where you place them. If your space is more of an open layout and kids are running around you may have to look at more hanging options and less table lamps. Utilizing areas that are up against the wall.
A question to ask is “What tasks do I want to do in the room?” Decide where you really need lamps first.
Measure to see what size you like. I have used other lamps in the home or even vases, using something that gives you a visual to see what size you prefer.
Also consider how the lamp obstructs the view of another person if it is positioned between two chairs. You may not want a large oversized base for that area. You may want it slightly taller.
When choosing the color and type of material for the lamp. See what colors you might want to bring out and the finish as well. Ceramic, metal, glass or wood.
Most importantly it is what you like and what you find pleasing to the eye. If you are still struggling I find sites like Pinterest and Houzz to be great ways to get my clients to see something more visually, to understand how the size and style will look.
Here is a great guide if you trying to buy a shade for your lamp from Lamps Plus