Set your camera securely on your tripod with all the moving parts locked down. Try and set up on solid ground and where possible, weigh your tripod down.
Set your camera to manual
Set your camera to manual exposure, and manual focus. Also make sure that you’re shooting in raw.
Set a high ISO
Set your camera to a high ISO. Start with 3200 and work from there. Using a high ISO will introduce some digital noise, but this is easily reduced in post production. Setting your camera’s in built noise reduction to on can help out with this.
Open up your aperture
Set the aperture wide open. You need to make the most out of having a nice fast lens and capture as much light as possible.
Calculate your shutter speed
The easiest way to do this is to use the 500 rule. Divide 500 by the focal length of your lens. If you’re not using a full frame sensor, you’ll want to use the focal length as a full frame equivalent. (e.g. A 10mm lens on a 1.5 crop sensor has the equivalent focal length of 15mm. Use that figure to calculate the shutter speed.)
Use live view to focus
Use live view to focus on the stars, racking the focus back and forth until the stars are the smallest, sharpest points they can be.
Hook up your cable release. Triggertrap Mobile is perfect as it lets you tap in the exact shutter speed that you want to use.