I find that the most helpful type of meditation to reduce anxiety is mindfulness meditation. Mindfulness meditation encourages you to focus on the present, which helps to reduce worry about the future or distress about the past. Mindfulness meditation is one of the most popular forms of meditation because it is easy to start, does not usually require a teacher or any classes, and it is accessible to most people.
These facts alone help to reduce anxiety because you do not need to make additional plans to meditate. You can simply stop what you are doing any time you feel anxious and start to meditate.