Good light is loads more important than any camera or lens. Going to the basics of photography or videography, you are capturing light. Light eminates from a light source, bounces around a lot, and ends up on your camera sensor. An attractive image comes down to great light, no matter the size or quality of the sensor it hits. It's common practice to buy an expensive $2000 camera, but you can never tell it costs that much, because it is filmed in a dark room with a lamp in the background. No matter what camera you have, I encourage you to practice as much as you can, shoot as much as you can, so you learn how to milk your camera as best as you can. The best way to do this is to invest in lighting. "Invest" might sound scary, but you would be surprised what you can get for little to no money.
The best (and cheapest) light source is right outside. If you turn your head and look up from your device you'll experience the most valuable tool for any visual image creator: The sun. That being said, you still need to learn how to use the sun to get the best results you can. Some of these tips are very simple tips, but are good introductory techniques to up the quality of your image.
1. Shoot on an overcast day.
This doesn't work for every look. Sometimes you want the bright, direct light that the sun offers. Otherwise, wait for a day that is cloudy and overcast. It will get you very nice, even, light without harsh shadows and squinting. Depending on the thickness of the clouds, you can shoot from any angle and get appealing light. The clouds act as a giant softbox and spread out the light of the sun, softening it very nicely. When in doubt shoot when clouds are out.
2. Wait for golden hour
The best (and most popular) solution is to shoot during golden hour. If you are unfamiliar with the term "golden hour", it refers to the hour before sunset or after sunrise. The sun is low in the sky meaning it is softer and at an optimal angle. The trouble with shooting in the middle of the day is the position of the sun being over head. This means you get unflattering shadows, especially on a person's face, specifically below their eyes. During golden hour the sun is lower in the sky, and avoids nasty overhead shadows. You also get a nice warm orange glow from the sun. Again, this look doesn't work for everything, but it is a good goal. The key is to avoid shooting during the middle of the day. The closer you get to sunrise or sunset, the better light you get. If you are worried about limited shooting time during golden hour, consider shooting during "silver hour".
"Silver hour" is the hour before golden hour at sunset, or the hour after golden hour at sunrise. The sun is still in a position that provides flattering light, which means you can get 2 hours of good light instead of just one for each respective golden hour
Definitely don't feel boxed in to just golden hour. Good light exists near that too. Just remember to shoot as close as possible to sunset and sunrise. Below is an example of an extended photo project I did where I photographed the same scene in different scenarios. The one on the left is shot just after sunrise. The middle is shot in the middle of the day, around 1:00pm. The one on the right is shot during golden hour before sunset.
3. Shoot in the shadows
When you have no option but to shoot during the middle of a bright sunny day, choose your locations and shots to avoid direct sunlight. Go in the shade and shoot there if you can. It will be cooler anyway! This way you will avoid the harshness of the midday sun but still get a nice, bright image. The thing you do have to consider is dynamic range. Since cameras can only handle so much of the range from light to dark, you could potentially lose information in the highlights. You risk this when you shoot your subject in the shadows, while the background is getting hit directly by sunlight. When the subject is correctly exposed, you will most likely blow out the highlights in the background. This isn't bad, but keep it in mind.
Buy cheap lights
If you are shooting inside, or just want additional light, consider picking up cheap lights. Lights can cost a lot, but they don't have to. Most likely if you have the budget for expensive lights, you know how to use them. The lighting setup below costed me ~$90. That included an LED light, two stands, a reflector, and a reflector holder. You would be surprised at the variety you can get with a single light.
You can see the totally different looks I'm getting. In practice, it's simple. Let's pick it apart.
On the left
A harsher, more dramatic look. I have a small LED light slightly above my head and pointing down, with a reflector on the left side to add a bit of fill.
On the right
A softer, brighter look. This I simply turned the LED light around and pointed it at the reflector. I bounced the light, and added more surface area to widen the reach and soften it.
Don't overthink it. Don't overspend. You can get softbox kits with 2-3 lights for $100 bucks. Cheaper lights tend to have pink or green tints, but that can be found in the $400-$500 dollar lights too. This is a must have to any kit. This $90 setup is incredibly versatile at it's pricepoint. Just keep in mind that you probably can't do much with it outside. The LED light is bright, but you have less control than you do indoors, and the intensity of your light and reflector is dampened in comparison to the sun. Below is a link to what I bought. You can easily overcomplicate what light to purchase. The main thing to decide is softbox vs. LED. There are advantages and disadvantages to both, with better, more knowledgable people out there to explain it. Google it. I went with LED because they can be powered via battery and are more portable. You decide for yourself.
The best way to practice lighting is to shoot it. Try it, experiment with it. Try anything and everything you want. See what you like and what works best with your kit. I encourage everyone to buy a simple lighting kit. Experiment with the looks you like. Go out at golden hour, try different times of the day and see the kind of light it gives off. The best way to learn is to do. Go. Do.