For me, my mental space has a much greater impact on my speech than the mechanics of how I actually try to speak. Things like getting enough sleep, eating right and exercising have a positive impact on my speech. Also, it helps when I cut myself some slack. I sometimes fall into the trap of thinking that anything but 100% perfect speech is failure. Even "normal" talkers don't have 100% perfect speech, and holding yourself to an impossible standard just destroys your confidence. Instead, work to develop your confidence (ie. improving your mental space), and give yourself gold stars for your attempts. One easy thing you can do is call a restaurant and ask them about their specials. It might go well, or it might be a train wreck where you get hung up on. The outcome is actually irrelevant, and if it helps, do the whole thing assuming that it's going to be a trainwreck. The point is to practice calling people and asking them things until you become the kind of person who feels comfortable calling people and asking them things. Any improvement on speech will come as a product of that. It's also helped me to find other sources of confidence: developing a creative interest that I can lean on whenever I start feeling down. Hope this helps.