As someone who lives with a slight speech impediment , I would rate my impediment as 4.5/10. What has worked for me is "thinking about and reciting" what I say before I speak. It's a common tactic many use , even those without speech impairment. Most don't even notice I have a speech impediment , and are surprised when I inform them. It is far from perfect but it's a tactic I have used and has worked well for me and others I have spoke with. hopefully my comment helps in any way.