Its easy to find tenants, but finding good tenants is never easy. Once you have found a good tenant , you would like them to stay. The key is to keep them happy.

Show them you care:

Return calls and emails in a timely manner
Always be polite
Get maintenance issues dealt with promptly

Go the extra mile:

Small tokens of appreciation like a handful of lollies at inspections are appreciated
Be sensitive about cultural practices like removing shoes before entering
Keep the property well maintained and a desirable place to live in

For long term tenants you might consider an annual upgrade. It can be inexpensive such as a nice new door mat or you could let the tenants choose a preferred improvement within a certain budget. For example they could choose between a new bathroom heater or a heated towel rail or a panel heater in a bedroom.

Above all, tenants like quiet enjoyment of the property, which after all is their home.