Meditation is always helpful to calm our minds, focus, bring mental peace. We have a mindset that meditation requires time, a proper environment, and a certain mental state. This mindset leads us to ignore/skip meditation because managing them all together is not easy. But do you know, meditation is not that hard? We can practice it simply in any situation and it's very helpful to reduce stress.
Breathing. I find this one the most helpful. Because anyone can practice this anytime like on the subway or on the office. Also, breathing practice is very easy to do. You can find several tips online to do this better. Don't worry thinking if you are doing this right. Just breathe deeply, it will relax your muscles and brain too.
Pick a positive line for you. A positive line can increase positive energy automatically. During stress moments, say that. Like 'I'm doing fine', 'It's okay I will do better'. Talk to yourself positively during a bad time. Say your name and talk in your mind continuously to motivate yourself.
Practice mindfulness. Focusing on the present moment is very necessary to ignore all that happening around and in our minds too. It helps to keep aside our stress for moments. Also, mindfulness improves concentration, focus, and observation. It helps to understand everything better.
These three are the most simple way I think anyone can do anytime. You see, meditation is not that taught. Just our small effort can make it happen. And, as I was saying we can do it anytime, anywhere throughout the day. Most importantly it automatically brings a state of mind which helps to reduce stress. You can try it. I think it's gonna help!