Your property(ies) first and foremost should run like a business! Take pride in your business and work to ensure that it runs smoothly and efficiently. Create effective protocols and processes, get organized and try not to take things personally. Build a solid business plan and follow that structure!
Nice homes attract nice tenants. And sometimes weird ones, but the moral of this story is that if you do nothing to present a great product for renters, then not-so-great tenants is exactly what you will attract. Take the time to invest in your property, spruce it up and research the appropriate materials. You don't want cheap finishes that will break easily. Strive for a durable, lasting product that looks good and says "quality" to a shopping renter.
Most landlord are not as familiar with Fair Housing as they should be and it is often to their detriment. Take the time to do the research, consult an attorney if need be and really make sure you KNOW understand all that Fair Housing entails. This is a great tip for avoid time in court and a terrible reputation as a lazy landlord. Be sure to review federal, state and local laws in order to make sure your business starts off on the right foot.
This seems like common sense, however many landlords do not have an effective screening process in place. Others are over eager and do not wait for the right tenant to come along. They quickly rent to someone who is not fully qualified only to regret the cost and hardship a couple of months down the road. The eviction process is messy and expensive, so don't be afraid to wait for a good fit. You need to be the aggressor in this process. Don't wait for a renter to come to you, because they will and they won't be what you are looking for. Marketing strategies are important, so learn how to market effectively in order to get what you are looking for.
Tenant screening, when not done properly, is not only tedious, it is risky. The sad truth is that almost everyone lies! Don't believe what you are told. Do the work of digging deeper. A basic background check isn't going to cut it. Check with previous and current employers and verify income. Talk with past landlords to learn about payment history and the general care a tenant gave to a former dwelling or lack thereof. It's best to do the work upfront rather than deal with a costly eviction down the road.
Take time to "tutor" your tenant in expected rules and guidelines which they must follow. Be sure to enforce an agreed upon consequence in the event that a rule is broken (usually a fine). At the end of the day, respectable landlords have no problem enforcing the rules. Instruct your tenant on the process for reporting maintenance issues and be timely with the repairs and do them right the FIRST time. You will find that landlording can be a lucrative and rewarding prospect when done right!