Man, so many choices for handlebars! This is a personal preference item for sure but there is many things to consider.
A handlebar's height is the measurement from the clamp area to the top of the control length or end of the handle part of the bar. The height of the handlebar can be adjusted by loosening the bar at the clamp area and adjusting forward or backward to your preference.
The rise measures the length from the clamp area to the handlebar's first steep bend. To lengthen the rise, you can use riser clamps to maximize the handlebar's overall height. If you are short, there are midget bar options.
The handlebar width is measured from one end to the other or the end of the left control length to the end of the right control length. Generally, most handlebars are constructed within a few millimeters of one another if not the same width altogether.
The sweep is best viewed by looking at the side of your bike. Also known as the "pullback" it is measured from the center of the clamp area to the end of the bars (control length) in a letter "L" shape.
The control length is the area for your grips.
The clamp area is the bottom of the handlebars where it clamps onto the bike. The clamp area is where you can add risers and other equipment to change the measurements and feel of your handlebars. The thickness of the clamp area is 7/8th or 1-1/8th -inch.
So, when the style or size has been decided, how does a person choose what brand to use? I am currently running Fasst Co Flexx bars and love them. When I ride with standard bars, they feel too rigid like there is no give. I do not notice while I am riding that the Flexx bars are bending/moving but without them it is a huge difference and more fatigue in my hands/wrists. Flexx bars are designed to reduce vibration with the use of rubber elastomers which help with arm pump, fatigue, and takes away the harsh pounding to the upper body. They work for me and that is what is on my bikes.
In the past, I have used Protaper bars, woods low. This is a good bar for shorter people. My dad being taller than me used woods high. What it comes down to, is trying different ones and see what works best for you. Tons of options out there!