First, determine the direction of your hair growth by rubbing your hand or a credit card across your face. The direction in which you encounter resistance is ATG.
Then, especially if your beard is coarse, hydrate your skin for at least three minutes (ideally during a hot shower), as this can reduce the force required to cut hair by up to 70%.
Next, apply a quality shave gel, such as Fusion® Hydra Gel Pure & Sensitive Shave Gel. This will help prevent nicks and cuts, and soften hair for a more comfortable and close shave. You can make use of Gillette SkinGuard Sensitive Razor if you have a sensitive and acne prone skin.
Finally, try shaving with the grain first and then ATG if necessary. Reapplying shave gel or foam before going ATG also can help.