There are several proven strategies that can help increase repeat orders. First, loyalty programs. If a customer realizes that their next purchase will earn them bonuses, discounts, or cashback, the likelihood of returning increases dramatically. Second, personalized recommendations. If you use e-mail marketing or push notifications, you can suggest products to customers based on their past purchases. Thirdly, quality of service: if you have easy navigation, fast support chat answers and prompt delivery, people will come back. Reminders for repeat orders are also important - for example, if you have a cosmetics store, you can remind the customer that they will run out of cream in a month and offer a discount. You can read more about such methods in this article:
https://www.starleaf.com/blog/tips-for-turning-one-off-e-commerce-customers-into-repeat-buyers/ - there are specific tips and examples of successful strategies. In general, the key is to give the customer a reason to come back and make the buying process as comfortable as possible!