It depends on what kind of mindfulness exercise you plan to do.
Simple mindfulness exercises can be practiced anywhere and anytime. Research indicates that engaging your senses outdoors is especially beneficial.
For more structured mindfulness exercises, such as body scan meditation or sitting meditation, you'll need to set aside time when you can be in a quiet place without distractions or interruptions. You might choose to practice this type of exercise early in the morning before you begin your daily routine.
Aim to practice mindfulness every day for about six months. Over time, you might find that mindfulness becomes effortless. Think of it as a commitment to reconnecting with and nurturing yourself.