Take a moment, and have a quick look at your contacts in some of your social media tools, like LinkedIn. How many people do you know with a decent profile photo?

Go ahead. I’ll wait.

Did you look? Think about your reaction for a moment: did you find yourself involuntarily making snap judgements based on those pictures?

Most people do; we can’t help it. We all need pictures for our profiles on LinkedIn, Twitter, Facebook, Slack, YouTube, and so on… especially if we use any or all of these platforms professionally.

So do you need to hire a pro to take a nice picture? Not necessarily; the principles of a good photo are simple enough. A good headshot should generally be brightly-lit, have a neutral background, and be taken from far enough away to avoid looking like a selfie (unless that’s the vibe you really want).

And frankly, corporate headshots can be problematic, too. I often find them stuffy and lacking in personality. You want to look relaxed and professional, not like a bison head mounted on the wall.

So if you’re going to do this yourself, there’s one basic rule that will help your photo stand out from the run-of-the-mill snapshot:

Never use your camera’s built-in flash.

Treat the flash on your camera (or mobile phone) like the can of soup that’s been sitting at the back of your cupboard for two years: Useful when you’re desperate, but not your first choice unless you’re out of options.

Built-in flash gives you only one type of picture, and this is it:

Turn the flash off and never turn it back on. By far, the best source of light for any portrait is a window. Window light is magic.

A window provides light that comes primarily from one direction, which helps make the subject’s face appear three-dimensional. At the same time, a window provides soft shadows, which are flattering to just about everyone.

In the above photos, you have natural daylight in a) a public market, b) a kitchen, c) a reception hall, and d) a restaurant. Good light for a portrait photo can be found in many, many places.

So what exactly do you look for? You look for a window that is large, with lots of daylight but not direct sunlight. The direct sun is harsh. Cloudy days can sometimes work for you, since cloud diffuses the light. But a sunny day, with your subject positioned out of the direct sun, is ideal. And look for a background that is neutral in tone.

You’ll want to place your subject close to the window, with the light coming from slightly to one side. Too much in front, and you start getting the deer-in-headlights look; too much to the side, and the deeper shadows will start making your subject look like a supervillain.

Experiment by moving the camera around relative to the window. Small changes can make huge differences. By changing the position of the camera a little this way or that, or by having the subject look toward or away from the window fractionally, you can make a photo that is more friendly or more dramatic. The right angle will depend on the subject.

When you’re out with friends or family, sitting at a café table or on a bus, pay attention to what the light is doing on people’s faces. You’ll start to notice what works for people.

Finally, you don’t need an expensive camera to take a great profile photo. It’s all about the light. So get out that iPhone and play!