Introduce yourself and state your intention. Ask permission before harvesting and (most importantly) abide by the answer. Take only which is given and no more than you need. Use it respectfully. Share. Tend the plant. Give thanks and leave a gift from the heart. Share its teachings.
Braiding Sweetgrass by Robin Wall Kimmerer — one of my all time favorite books — calls this unwritten code 'The Honorable Harvest'. This way of being is not only reserved for foraging or wild harvest, but can be weaved throughout your days in the most simple of ways.
Perhaps you're picking Parsley to scatter on your morning eggs or Lemon Balm and Mint for a herbal tea. You might want to harvest Calendula or Chamomile to dry and infuse or place fresh into a vase. It may be the vegetables picked before dinner time to nourish you and yours. All interactions can be an opportunity to build relationships and deepen connection with individual plants and the plant realm as a whole.
Nurture her and she will nurture you.