Whichever you use, you have to know how to use the light. With both, you will be using light modifiers (reflectors, translucent panels aka scrims, etc.). A reflector can be hand held, or you can use a building, reflections of light from sidewalks, sand, etc. You can also block light (shade from trees, umbrellas, buildings, etc.). The smaller and farther away the light source, the harder the light. How do you decide which ones will work best to get the results you want? Experiment and practice. And take classes (free from CreativeLive).
All the photos below were taken at the beach (Dockweiler Beach in Playa Del Rey, CA) on September 19, 2015. They were shot with a Canon EOS 40D and a 24-105mm lens. The first few images were shot in the wrong mode, causing the exposures to be off by about two stops (was supposed to be Aperture prioity, which means I set the aperture and camera determines the speed), but the dial was set to Manual exposure. The dial may have accidentally rubbed against something and moved from Av to M. I had shot maybe around 30 images before I found the mistake. Luckily, I shoot in RAW mode (gives more leeway as all the information from the image is there, unlike shooting jpg, which does in camera processing and throws away of lot of image information), and combined with post processing in Lightroom, was able to get the following images. Because the exposure was off by at least two stops, the resulting images, after adjusting the exposure, were grainy/noisy. To minimize that, the images were smoothed out, which is why they are not needle sharp.
All the same applies to the next two photos, but one was taken in direct sunlight around high noon, and the other in shade. In all these photos, the sand acted as my reflector.
Direct Sun
Should you shoot in Manual, Aperture Priority, or some other setting? There are those who will say to always shoot in Manual, and you should know how to do that. Depending on what I'm shooting, I will either use Av or M. If the light is not going to change, or if there is a lot of white or black that might trick the meter, then use M. For most of the photos on this day, except where I had made a mistake, I used Av and it worked fine. Especially around sunset, when the light changed fairly quickly, as in the shots below.
After dark, with flash, Manual works best for me. If you set it to Av in low light, the shutter will remain open far too long to hand hold the camera, and if anyone moves, you'll get some weird results! Here's a couple of flash shots at night in Manual mode.
So, a summary of what you should do to get the photos you want:
1. Read and study the camera manual. Perhaps there is a book about it, too, you can read.
2. Learn about composition, lighting, lenses, etc. through online courses, books, etc.
3. Practice, practice, practice - using different settings, f-stops, times, ISO's, lighting, composition, etc.
4. Keep repeating the above.
5. Oh - don't be afraid to ask someone like me any questions.
Hope you've enjoyed these photos, and have a wonderful weekend.