When you're making people photos in existing light, you need to be aware of how the quantity and quality of that light will impact your results. You'll probably start out by following "rules" you've heard, but, as you begin to understand your camera's characteristics better, you should be able to look at a scene and have a good idea how to best use the available light. Practice with that in mind. If you've been around photographers for more than 15 minutes, you've heard of the golden hours, just after sunrise and just before sunset. (I even have an app that will give me those times for my current location.) The reason the light is so great at these times is the sun is coming from a lower angle with rich, warm light. Remember, you aren't usually trying to eliminate all the shadows. The shadows define what the light illuminates. Its passage through the atmosphere to your subject gives it a very pleasing look, even if you're just taking snapshots.
The "worst" light is at midday because the light is so strong and directly overhead. It can cause harsh shadows and create a photo lacking in dimension (flat). But you can't avoid this time of day completely. There are several things to make this light more useable.
Some photos actually work just fine in this strong light. The photo below works because you expect a strong light when you see kids playing in a fountain in the summer. The kids are spread throughout the spray, giving it a little more dimension, and the spray obscures the harsh shadows. We don't worry about the light on their faces because you can't see them. The kayaker works for the same reasons.
You may decide to shoot in the open shade, under a tree, to defeat the direct sunlight's effects. This works just fine, but it also eliminates all shadows, again giving you a flatter photo. Also, shade can give your photo a bluish tint. You can eliminate this with your camera setting, or fix it in post processing. This photo was taken just after noon, but the shade gave me even lighting. I used a shallow depth of field to blur the background and separate my subject from the background. That keeps the photo from looking too flat. Unfortunately, I was standing in sunlight so bright that my subject is still squinting a bit.
Be careful when your subjects are under trees that you don't get a dappled lighting effect like the photo below. I don't think this one is too distracting, but you can see how it affects the colors and shadows on his shirt. The other disadvantage to trees are branches that go into your subject's head. I can fix these in Photoshop, but it's always better if they aren't there at all. This one was also taken at 1230.
I did a better job on the next photo. I'm also in the shade, and my subject is relaxed. In this shot, we were in a small patio. The light is coming into the patio from the camera right. By turning him so the light came in from the side, I was able to generate some soft, defining shadows on his face.
If you have a room with lots of light, you can shoot inside during the middle of the day. The setting for this photo is a great room, with skylights and big windows. I also had a reflector handy to add some extra light.
So, whenever possible, try to shoot when the light is best. But don't stop shooting, just because the light is not ideal. Shoot photos that fit with the strong light or use areas that can help you ameliorate those conditions. It's usually better to get something instead of nothing. And keep trying to get your subjects during those glorious late afternoons, inside golden hour. This one was shot the other day on just such an occasion. No post processing or light modifiers here, just beautiful, natural light. Have fun.