According to my Experience (As I was working with an company and With another account on Fiverr as a Junior Designer) You should deliver such things to satisfy customer :
1 : Deliver Quality Work .
2 : Look for the Customer Satisfaction .
3 : Give Several of modifications until client becomes happy .
4 : Provide work within the given time period .
5 : Mostly customers are very nice to you . You should also be polite with them . etc
Looking for My First Order (ON THIS ACCOUNT) to satisfy my first client and Proof myself