The first rule of manipulation in general, but especially at work is: Be Subtle. The moment others consider you to be manipulative, they will dissect everything you say and do in order to protect themselves from being manipulated. In order to be effective, you must have the trust of those you want to influence.
Environment: Your work space should be, clean and very well balanced. Not too many personal pictures, but one or two are good. At least one should be of you with a close friend or a dog (shows loyalty and implies you aren’t completely self centered). A healthy plant is good, and sickly plant is very bad.
Dress: Wear professional clothes, preferably dark in color. Dark colors are perceived as more powerful. If you need to know how someone is feeling, or want them to be more open with you, it is better to wear lighter, pastel colors.
Refreshments: A recent study showed that people will think more warmly about you if they are holding something warm while talking to you and looking at you. So, offer a cup of tea or coffee.
Conversation: Casual mention, in a positive light, someone who you know the other person holds in great esteem. It is best to do this at a time when it isn’t OBVIOUS that you know the other person’s feelings. If you are in your boss’ office and they have a picture of Reagan, you don’t say: I like Reagan. Later, when you are standing in the hallway together, you can quote Reagan to make your point.
If you don’t want to be manipulative, and still want to get your way, you can use my three rules: be polite, stand firm and be helpful.