Tipping is not expected, but is commonly practiced in the emirate. Gratuities to hotel and restaurant staff are at your discretion. 

Many fine dining and high-end restaurants may add a service charge (usually around 10%) and a tourism levy of 6% to your bill. These charges are often included in the menu prices and the menu will denote when they are. 

If you are very happy with the service, it is not expected but quite common to leave a tip on top of the already included (16%) fees & service charges. If these charges are not included, then you may like to add a 10-15% tip to the total bill.