Might as well put it in beginner mode to take a short flight.
Also mentally gauge the height of the tallest obstacle that is in the area. Set the Return to Home Altitude to this measurement and add about 40-50 feet.
Also to use the Return to Home feature one must press and HOLD the button on the Remote Controller. A quick press will not usually engage the Return to Home.
Try and always fly with a fully charged battery.
Always position the Mavic pointing away from you before you gain altitude.
Make sure there are no obstructions above you. Tree's , overhangs , etc.
Hover for a few moments with fingers off sticks. Make sure you hear or see Home Point Recorded. Get the feel for what its like when you take your fingers off the sticks and the Mavic hovers perfectly in space.
This will be helpful if you get into a panic situation in the future and need to just breath and stop to plan your next movement of the craft.
Remove the Gimbal Clamp! Make sure to do this or you can potentially do damage to the gimbal motor.