How to be effective in a debate.
Debating is Task Oriented, not Personal. Expert debaters make fewer better points and are more willing to find a common ground. Making a lot of arguments for your position is worse than making a few very strong arguments for it. Your argument is only as strong as your weakest point. Once people start not buying the arguments you make a fall like dominoes. This recommendation, though, is not a panacea. The right argument is situation and person dependent.
Also don’t use a straw man for an opponent’s arguments. Use address their strongest argument, Finding Middle Ground, and use Calibrated Questions to find where the debate can go. A good question is “what evidence would you need to see to change your opinion”?