Have a plan and stick to it. Make sure you know what actions you will take in case things go awry and stick with it. If you have to leave the store, do so. It may not be the most convenient choice, but it’s the best choice for you and your child.
Discuss the outing before you go. Talking, writing, or drawing what you will do will help your child know what to expect. If your child can make a list and check it off, that can be even more helpful. That way they know the plan and will lessen their anxiety. If you are going to the grocery store, let your child know if they can or cannot have a treat today. However, it can be rewarding to let them choose between 2 cereals you approve.
Be prepared. If you know your child needs a communication device, drink, snack, etc for the outing do not forget it.
It may be helpful to have your child earn a reward for good behavior when they get home. This can be done verbally or by having a pad and paper around indicating how many stars they need and how many have been earned.