I am constantly working to be both a better player and better game-master. I read anything I can get my hands on in order to increase my skills at role-playing and thus the fun for everyone at the table. I am not content with mediocrity; I want to constantly bring my A game. Many places have suggested the techniques learned in an Improv troupe. These can greatly improve your aptitude at the gaming table, but it is sometimes difficult to get involved with one. I wanted to let you know there is an organization out there that is easier to get involved with and will help you be a better player and GM, Toastmasters. For those of you that don't know, Toastmasters (TM) is an organization that is all about making you a better speaker.
When you go to your first meeting, you will realize they love to have guests at the meeting. Most TM clubs have a typical flow for the meeting and meet anywhere from once a week or once a month. The meetings themselves run anywhere from an 45 minutes to 2 hours depending on their frequency. There is also speciality clubs that work on anything from humor to evaluations.
Once you become a member, they will ask you your goals. There is typically two things they work on in the beginning. First thing is to get you comfortable with talking in front of an audience. This may not be much of a hurdle if you are a GM; especially if you are one used to running at gaming conventions. A scenario where you never know who your players will be so you get comfortable very quickly. If you ever have aspirations to be a convention GM the ability to speak in front of strangers will be required.
The second major thing they work on at the beginning is removing crutch words from your vocabulary. These are the "ahs," "ums," double words, etc that people use to fill in when they are either nervous or are trying to think of something to say. I think the GM, especially in the traditional GM role, is as much about story telling as acting. Nothing hurts a storyteller more than a distracted audience and being a poor speaker can be distracting. Simply removing the crutch words will give you a leg up on your GM skills.
You set your own goals. These are just two most common goals for people who recently join TM. I personally work on my swearing which my wife would like to see less of. One member in my club is a trainer and joined to become a more concise speaker. Another wanted to make sure that he had the confidence to give a speech at his daughter's wedding. Whatever your goals are as a GM, Toastmasters can help. Find a club near you.