Manager employment should require that people be trained to know how to turn their staff into a team, along with skills on how to treat and communicate with people that will make them want to please you, and the company, and always try their best every single day. It also makes employees that may have never considered manager jobs think again, realizing that jobs management isn't that difficult after all. This can also look very good on a resume and can even be included on a cover letter.
One important way to motivate people into working as a team is giving them praise regularly, and give incentives to do a good job. For example, if you are a manager at a restaurant, you can motive people into working together if you offer a cash bonus to each person if they make a certain amount in sales. Even $10 here and there to each person on the shift will be greatly appreciated. When they have done really well on a difficult task, or are keeping up with the pace, saying 'thank you' and 'nice job' lets them know you noticed how hard they tried.
People with manager jobs should really try to get to know at least the full time, regular employees as much as possible. While you don't have to be their best friend, a card on their birthday or at the holidays is a really inexpensive way to let them at least think you care. For landlords who have apartment managers, this can be expressed by sending them some free movie certificates or something like that.
It takes a lot of self discipline in all kinds of manager jobs as there are many responsibilities. One of the ways to make workers feel important is to ask them to help you when you are overwhelmed. Ask them to help you do inventory, and you may even ask if they would like to get some extra hours on their pay check if they come in. Another way to help make your team work properly is to address issues between co-workers right away, rather than brush them off. You can help them to resolve the issue in a civil manner, and if it can't be settled, maybe their shifts can be switched around.
You can find much more helpful information online, and through other resources. One can certainly put up a suggestion box that all your employees have access too. Make sure that you really do check this regularly, and if someone has an idea you think might work, maybe discuss it with them. You will find that this is a great way to get people to not only work as a team, but also brainstorm solutions to all kinds of problems.