If you really believe that you are going to be able to wing the speech on the day then you are going to be in for a big shock because for the person that is not used to giving groom wedding speech in front of people you are going to be that person that looks and acts like a nervous idiot. However you must understand that if you want to avoid all chances of looking like that person then you must stop wasting anymore of your time on that which just does not work and do that which is going to actually help you. You must stop hanging out with your mates in the weeks prior to the wedding and just put in the work that is going to result in you giving the best speech of your life. Do this and I can promise you here and now that you are going to be able to give a great speech that people in the audience are going to be remembering years later.