In the modern world the typical landlord needs a full-time job besides owning a few properties they rent out. Many people go into the landlored business unprepared. Here's a few hints to help you be a good landlord when dealing with less than perfect renters.
Use a good rental application that will help you screen out potentially bad renters. Holding out for a quality tenant is a lot better than taking whatever random tenant comes along.
Make the applying process detailed and cautious, with a clause to let you pull credit history and general background information. After the application has been filled out and signed, you should check up on things like financial history, employment, history with any previous landlords, and so on.
Sign a lease that is particular to your state. Since state laws for landlords and tenants are highly specific to each state, you should have a state-customized lease agreement taking into account all the little details of the state. If you use a more generic lease agreement, your position in a legal dispute will be weakened.
As part of your services as landlord, you should have a quick response time to requests for repairs and maintenance of the property. If you're lazy on this, you could end up with a bitter tenant that causes many other problems, or risk damage to your property.
You don't have to do every little improvement or upgrade or fix that your tenants might want, of course. If something comes up you don't really want to do and feel isn't necessary, just say you can't afford it. This resolves the issue without making the tenant hostile.
Similarly you should be perceptive of and respond speedily to general tenant disputes. The longer you leave problems and disagreements alone, the easier these things can turn into pricey fights in court, with no way for you to win without spending money you'd rather not spend. So treat your tenants courteously, sit down and talk to them and listen to what they say.
For complicated matters you may want to have a copy of the lease agremeent on hand so you can point to it or refer to it yourself when necessary, since a good lease agreement will cover many disputes and disagreements the tenants might have.
And should you be losing a tenant, try to help them move out with a minimum of hassle. Evicting them is your right but it's usually not worth it in terms of profit.
When you talk to your tenants, be sure to keep a record of significant communications and have the papers signed by your tenants so that there's a written agreement on what was said. A paper trail could save you a lot of headaches in court.
And last, try to keep your rent-collection duties as automated and self-running as possible. Since many renters will try to delay on their payments and play on your compassion, it makes collection of rent one of the harder things for landlords to do efficiently.
Don't let it be an emotional thing. It's a business, not charity. Treat your tenants professionally and expect them to behave professionally in return, and if they're late, send an eviction notice immediately.
A zero tolerance policy will let people know where the lines are so they won't try to nudge you into giving them more slack than they should legally be entitled to. Keep this simple rule and all the rules prior to it in mind, and you'll be able to run your rental business cleanly and effectively, rather than as a shaky little side gig.