Start leaving your child with people you trust at an early age. Start out with short periods of time and then slowly increase the length of time. It will make your child and you feel more comfortable with the separation.
Never sneak away when you leave your child. Create a good bye ritual. Include a hug, a kiss, and an “I love you,” You might also want to kiss the palms of your child’s hand and have your child save those kisses in their pocket. If they miss you, they can reach into their pocket, pull out a kiss and place it on their cheek.