1. Good tenants hate being disturbed.
One of the reasons they are good tenants is that they are good neighbors, that they show consideration of the people who live around them. So when another tenant throws wild parties all night long, they hate it.
Other kinds of disturbances they hate would be the drug dealers next door, and the traffic, unsavory characters and bad behavior that goes along with dealing drugs. That kind of disturbance will get them to move as fast or faster than loud parties next door. In fact drug dealers in an apartment complex or even in the neighborhood tells them that the neighborhood is going downhill. Good tenants don't like to live in bad neighborhoods.
They hate it when landlords do things to disturb them, too. Any number of things would be possible irritants. It might be someone mowing the lawn at eight o'clock Saturday morning, just when they were looking forward to a quiet, peaceful breakfast on their balcony. It could be the leaf blower at about the same time on Sunday morning.
Good tenants hate having their lives disrupted by repairs, either in their units or in common areas. It's bad enough that road construction made it just about impossible for them to get to work that morning. But you expect rude, arrogant treatment from city crews and employees. But then you finally get home from work only to find that there is a huge trench across your parking space. Then, you have to walk all the way around the building just to get to your front door because everything is torn up.
As a landlord you have control over every one of these aggravating situations.
Immediately responding to noise complaints is essential. Tenants agreed when they signed the lease that they would not do things to disturb their neighbors. In fact you may even have specific rules in addition to the lease regarding noise. Enforce them.
There are times when a landlord has to be the bad guy. That's why apartment and landlord associations sell forms that tell tenants to stop being bad neighbors. Insisting on good-neighbor behavior is part of managing rental property.
Evict drug dealers. If you have any real evidence, you can evict them for cause. If your tenants are all under lease, you will have to evict for violating the terms of the lease, anyway. If they are month-to-month, and you don't have hard evidence of drug dealing, but know it's going on, simply give them a 30-day notice to move (or whatever is required in your state).
If the drug dealing is going on in a property that is not owned by you, work with neighbors, the property owner and the police to do what's necessary to get rid of the drug dealers.
When you make repairs or have them done, think of the needs of your tenants first. Yes, sometimes you have to make major repairs that inconvenience your tenants. Work with the contractor to make it as easy on your tenants as possible. Prompted toward working his brain in that direction, your contractor will probably be able to come up with ideas for minimizing inconvenience.
Whatever inconvenience there is going to be, tell your tenants beforehand. Write a letter explaining the work that is going to be done, how long it will take, and what kind of inconvenience they can expect. Always be thinking of the safety and security of both your tenants and their property (such as their vehicles), too. For example, in the case of their parking space being unusable while repairs are being made, make sure they have an equally secure parking space. Criminals are always on the lookout for easy targets. Cars parked where they are not visible from a building will catch a crook's eye like a homing beacon.
Then, when everything is done, send your tenants a gift thanking them for their patience, and a note reiterating the repairs that were done and how it will make their home a better place to live.