How to say yes without being seen as a yes-man?

If you agree with another person, you can say "yes" which is the norm. But, if you keep saying yes without anything to add, it can make you sound like a cardboard yes man. There are some ways you can say yes that can give you a upper hand:

• You can rationalize your reasons of agreeing so that it seems you have thought about it. 

• Or, you can summarize up what the other person has said in your own words. People has different style of speaking. So, rather than saying just "Yes, i agree with you. You sound logical. It can support the project." which sounds so cliche and wooden. 

• Or, ask questions but with a purpose to confirm what was said. Repeat the whole idea but in your own words, in other words confirming what the other person say, and checking with them with some questions thrown in for the other person to confirm (in return) to agree with you. See, how you can turn the table around. The other person now say "yes to you" rather than you say yes to him. Because you are repeating in your own words and asking him questions to confirm your understanding, he has to agree with you in front of others to agree that it's what he had just said.

PS. Ask intelligently. But, if you don't know or blur about what he had just said and if you're asking too much dumb questions, you can appear dumb. The note here is that you somewhat know and you are getting him to say yes to your understanding so that there is no misunderstanding later and to enhance your understanding.