Gear Check and Environment Setup

Start with the boring stuff. It saves time later. Grab your camera body and the lens you actually use, not the one sitting in the bag gathering dust. Check the battery. Put it in the charger if it’s below half. There is nothing worse than packing a bag, driving to a location, and seeing a blinking red icon the moment you turn the power on.
Clean the glass. Use a blower first to get the dust off. If you wipe a lens with dust on it, you grind sand into the coating. Then use a microfiber cloth. Wipe in a circle, not a zigzag. Check the memory card. Format it in the camera, not the computer. This reduces the risk of file corruption later.
Look at the light. Where is the sun? If it’s high noon, the light is harsh. Shadows will look like black holes under the eyes. You might need to find open shade—the kind of shadow you find under a tree or the side of a building. If you are shooting indoors, turn off the overhead lights. They cast weird colors. Use window light instead. It’s softer and it’s free.

Switching to Manual Mode

Turn the mode dial to ‘M’. It feels intimidating. That’s normal. The camera won’t help you here, but it also won’t fight you.
Set your ISO first. This is the sensitivity of the sensor. If you are outside on a sunny day, keep it low, like 100 or 200. If you go inside, you might need to push it to 800 or 1600. Watch out for noise. If you zoom in on the LCD and the image looks like it’s covered in static, the ISO is too high. Drop it down if you can.
Next is the aperture. This is the hole in the lens. It is written in f-numbers like f/1.8, f/5.6, f/16. A low number like f/1.8 means a wide hole. It lets in lots of light but makes the background blurry. A high number like f/16 means a tiny hole. It keeps everything in focus from the front of the scene to the back, but it needs a lot of light or a slow shutter.
Finally, the shutter speed. This is how long the curtain stays open. If you are hand-holding the camera, don’t go slower than 1/60th of a second. Anything slower and your own heartbeat will blur the image. If you are shooting a moving dog or a car, you need 1/500th or faster. Adjust this dial until the little meter in the viewfinder hits the center. Zero. That is the baseline.

Focusing and Composition

Autofocus is good, but it isn’t smart. Switch your focus mode to “Single Shot” or “One Shot” if your subject isn’t moving. Put the focus point right on the subject’s eye. If the eye is sharp, the photo works. If the eye is soft, the photo is trash, no matter how good the lighting is.
Press the shutter button halfway. Hold it there. Recompose the shot if you need to. Don’t just spray and pray. Think about the edges of the frame. Is there a tree branch growing out of someone’s head? Is a trash can cutting into the corner? Fix it now. Move your feet. Zoom with your lens.
Check the background. A busy background kills attention. If you are shooting a portrait, move the subject away from the wall. The further they are from the background, the more the background blurs. It separates them from the noise.

Troubleshooting Common Issues

The image is too dark. You underexposed it. Look at the meter. It’s pointing to the left. You need to do one of three things: lower the f-number, slow down the shutter, or raise the ISO. Which one? It depends. If you need motion blur, slow the shutter. If you need a blurry background, lower the f-number. If you can’t do either, raise the ISO.
The image is too bright. It’s blown out. You lost the details in the highlights. Do the reverse. Raise the f-number, speed up the shutter, or drop the ISO. Highlights are harder to recover than shadows in editing. It is better to be a little dark than completely white.
The photo is blurry. Was the subject moving or were you? If the whole frame is blurry, you shook the camera. Use a faster shutter or a tripod. If the subject is blurry but the background is sharp, the subject moved. Speed up the shutter. If a specific spot is blurry but the rest is sharp, you missed the focus. Take it again.

Review and Refine

Chimping. That’s what photographers call looking at the LCD screen after every shot. Do it. It’s not a sin. Zoom in all the way. Scroll around to the eyes. Are they sharp? Is the skin tone looking natural or too orange?
If you don’t like it, change it. Don’t wait until you get home to look at the files. You can’t fix a bad exposure or a missed focus in Lightroom. You can only make a good photo better. Shoot ten different angles. Crouch down. Stand on a chair. Shoot from the hip.
When you are done, put the lens caps back on. Dust is the enemy. Upload the photos. Pick the best three. Delete the rest. Hoarding bad photos just clutters your hard drive and confuses your portfolio. Being ruthless is part of the job.