1. "I pay your salary. You have to do what I say." Have you not heard? It's the 21st century. Threats and power plays just do not cut it anymore (and they were always a terrible way to manage). Yes, you pay people's salaries but that doesn't mean you're their lord and master. You are their leader, however. Leaders lead by inspiring, teaching, encouraging, and, yes, serving their employees. Good leaders never need to threaten. So keep your word, set a good example, praise in public, criticize in private, respect your employees' capabilities, give credit where credit is due, learn to delegate, and when you ask for feedback don't forget to respond to it. (Another sentence to be avoided: "Do what I say, not what I do.")
2. "I don't want to listen to your complaints." Hey, boss, you have this backwards. You do want to listen to employees' complaints. That's part of your job. You should be actively seeking feedback, even negative feedback. It may be annoying, even painful, but that's why you get the big bucks. Complaints point to where your processes and practices need improvement. And even if a problem absolutely can't be helped, allowing your employees to vent can go a long way toward restoring morale and building loyalty.
3. "I was here on Saturday afternoon. Where were you?" This kind of "subtle" pressure to work 24/7 is a good way to burn out your employees. You won't get that much more productivity out of them, and you will destroy morale. You may choose to work seven days a week. That's your call. But your employees shouldn't have to. If you observe that they are working way more than their job descriptions call for, consider that maybe it's because you're overloading them. Look for ways to fix this problem.
4. "Isn't your performance review coming up soon?" Maybe you're trying to motivate an employee to do a better job. Maybe this is just a ham-handed way to remind underlings of who has the power. Who knows. Either way, a statement like this is not only tacky and passive-aggressive, it's ineffective. If you really want to motivate people, consider giving them a stake in the success of your enterprise. Show employees you value them. Let them know what they have to gain by doing a good job. The results may surprise you.
5. "We've always done it this way." Want to crush your employees' initiative? This is a good way. News flash: Your employees may actually have a pretty good idea of how to do their jobs. Maybe they know even more than you. Your job as boss is to encourage them to have the energy and motivation to be innovative. In fact, employees who come up with better ways to do things should be celebrated and rewarded. (Hint: Cash is nice.)
6. "We need to cut costs" (at the same time you are, say, redecorating your office). Nothing breeds resentment more than asking employees to tighten their belts while you, to their eyes, are living it up. Even if the office redecoration can be totally justified in business terms, or the budget for it was a gift from your uncle, it still looks hypocritical and is demoralizing. Being sensitive to other people's feelings is good karma. Leading by example is the best way to lead.
7. "You should work better." Managers need to communication expectations clearly, to give employees the tools they need to do a good job, to set reasonable deadlines, and to offer help if needed. When giving instructions, ask if they understand your instructions. Don't assume. You may not be the stellar communicator you think you are. If your employees are making mistakes, or not performing up to par, consider that maybe it's because you're giving them vague instructions like "you should work better."
The bottom line is that in the workplace respect, a little tact, and a good attitude go both ways.