Do the following:
1) Set your gig professionally.
2) Your gig should attract clients and the conversion rate should be good.
3) Provide excellent service and customer support.
4) Fulfil and exceed your promises to the clients.
In addition, you should also mention a refund policy on your services (FAQs). It will help you in dealing future requests. Buyer satisfaction should be first priority. It will also help buyers to set "expectations" that when they can ask for refund and under which conditions refunds is not possible.
Yes, I am using it since March 2016. Considering you as a top rated and pro seller, I want to learn from you as learning never stop. @filipdevaere I am hopeful that I will learn very beneficial information from you.
You need to see how many impressions are giving you order and how much impressions you are getting on daily/ weekly basis. Then improve your conversion rate if it is low.