The Door In The Face!
The door in the face technique is a psychological trick used in influencing people to comply with a request.
The door in the face technique works quite simply by asking people to commit to a request in the knowledge that it is too big an ask for them to agree to, then following up with a smaller and more reasonable request.
In being unwilling to agree to a large request, people are then more likely to oblige a second more reasonable request than they were if they had been asked only to meet this request alone.
The Foot In The Door
The foot in the door technique is a persuasion tactic that works the other way round from the door in the face in that rather than asking people to commit to a large request, they are asked to fulfill a series of small requests and then asked to fulfill a larger request.
In meeting a number of small requests people are then more likely to agree to a bigger request than had the bigger request been asked alone.
Manipulation
While there are a whole host of persuasion tactics from psychological tricks like the ones above to covert hypnosis, in the long run manipulating other people for reasons of self interest generally doesn't work.
While people may not consciously be able to figure out when they are being manipulated into doing things they may not ordinarily do, at some level their senses will generally alert them to someone who does not have their best interests at heart.
The easiest way to influence others is by being authentic and wanting what is best for them. Proposing offers that benefit yourself while genuinely helping someone else achieve something they desire is probably the best option.
If you want to influence people, be a positive influence.