Be present
Being totally present in the moment and aware of what you're doing and where you are is what mindfulness is all about. It involves paying great attention to your thoughts, feelings, and sensations as they occur. Because it prevents you from responding to or feeling overwhelmed by distractions and pressure, mindfulness is a simple and effective way to reduce stress.
For example, if you're anxious about a looming deadline, you could notice after a session of mindfulness practice that the deadline will occur in the future, but it's causing unnecessary anxiety right now. Being aware of unneeded tension is a benefit of being present. It may even help you in being more productive. Paying attention to your body's feelings and the surroundings around you is one of the best ways to become more grounded at the moment. Concentrating on your breath is an excellent starting point.