Plan your photo shoot - Plan your outdoor photo shoot ahead of time. Use an app to help you find the perfect light conditions, time and location.
Visit the location - Visit the location during the day to find the spot that will give you the winning composition.
Arrive early - Get on the site at least 30 minutes before sunset.
Prepare your camera - Now it is time to set your camera. Read the steps below (6 and above).
Stick to your location - Resist the temptation to change places. Relax and stay where you are. The sun will go down fast.
Shoot in Raw - Set your camera to shoot in RAW format or in RAW+JPG. I generally shoot in RAW and process my files in Lightroom. For more information on the difference between RAW and JPG, read this article.
Aperture Priority - Forget the manual mode. Make it simple: use the "Aperture Priority" mode and adjust the aperture to f/8 which is a safe value to get the whole scene in focus.
ISO - Select a low ISO value from 100 to 200. Higher ISO values are unnecessary since you face the sun. Select a higher ISO if you need need higher speed values.
Shutter speed - In "Aperture Priority" mode, the camera will adjust the shutter speed itself. Generally speaking, the shutter speed shall not be less than 1/60 sec to avoid blurry shots. If this is the case, gain speed by increasing ISO.
Tripod? - You don't necessarily need a tripod but if you have then use it. If you don't, that's not a problem. You will have enough light to photograph the sunset handheld but check your shutter speed and keep it above 1/60 sec or higher if you zoom in.
Exposure compensation - The most important point: OVEREXPOSE. Facing the sun, the camera will be fooled by so much light and will automatically underexpose. You must balance by overexposing intentionally. Use the exposure compensation dial to overexpose by 1 or 2 stops (check your user guide). You van learn more on exposure compensation here.
Shoot and check the histogram - Check your camera histogram each time you take a picture. It will show you if your shots are correctly exposed. If you are serious, the histogram is a tool that you must learn to use. I do check the histogram each time I take a picture to find the optimum exposure settings. To learn more about the histogram, check your manual and read these articles here and there.