How to be more influencial

I applied simple method to check my influential behavior, I don't know if it is a good method or not. Last week in term-break, we went for a trip to Subic, I observed while making decisions about place to go or hotel to stay etc. I was little incompetent in convincing people.
Is it a good observation or method of observation?
I also tried to read few books from library about becoming persuasive by Harward Press.
Sir, I need your help in this area of development. What would you suggest me to improve my influential skills ? Another thing is, I find it difficult to make strong decisions which may hurt people and hence while discussing Wyeth case, I recommended to give people time for improvement.
Also, I want to share little personal change that I encountered and its relation with the Johari window observations. I don't know, but after coming to AIM, I became little more introvert it might be because study load. But my Johari window observations were very strange and made me think that is it a really improvement.
Attributes I selected in Open Spot (Arena) were

adaptable
extroverted
friendly
intelligent
shy

But only "Intelligent" attribute is strongly matching (40%) with the people's observation. Also most of them observed me as "independent" & "bold" I thought myself exactly opposite of these. And hence I tried to relate it with my increased introvert. This is because I wanted to discuss my behavioral change.