Winston Churchill had some good ideas
Back in my younger days, I used this to make a sale.
The left hand column must always be totally blank. In the right hand column I would add all the benefits the prospect would get by buying my product. When I finished, I'd hand the A4 sheet to him and ask him to fill in, on the left, all the reasons why he shouldn't buy the product. Of course, when you do that, the brain freezes and he would be lucky to list two or three.
As a group leader for Leave.EU, I thought I'd use the same powerful tool to persuade people on the cusp or leaning towards staying in the EU to change their direction.
Naturally, the died in the wool people who hate our country couldn't be pursuaded.
So take an A4 sheet any sheet, use the back of a letter if you want. now add "Why we should stay" on the left half, and "Why we should leave" on the right.
Then write down all the reasons why we should leave on the right hand side, dovetail them to the other persons possible interests, in their home, or job if you know them well enough!
This way you might counter any possible arguments they may think of before they occur.
Fill the right hand column, note that a certain amount of homework is necessary before you attempt this if you really want to succeed.
Here is a sample page, OK, I have already typed in the right hand column, you shouldn't. It has to be spontaneous, which is why you need to rephrase good arguments into short sharp sntences.
Have fun but remember, we have to win this battle.