This is a good short video showing you 7 ways to get what you want.

I’ll list the 7 ways although the video does go into more detail:

1. Give compliments.
2. Repeat things back – it shows you are listening.
3. Ask for more than you want – the other person may refuse and then when you come back with what you actually want you may actually get that.
4. Use names – most people do not do this, and the video does not mention a negative aspect of this, do not overuse this, for example using the persons name with every sentence, you will sound manipulative.
5. Listen more.
6. Use flattery – but sincerely, most of us we are attuned to false flattery.
7. Ask the other for something when they are tired – then they will probably do it the next day; this does work but can be considered quite manipulative.