Passing the personality test is always something that will help. Remember that in most DWI's you are being recorded. If you come off polite, not only will the officer like it, but so will a jury of your peers.
Kindly Refuse the Breath Test
You have the right to refuse the breath test. The machines are not perfect and are subject to error, and you certainly do not want that error causing you a conviction.
Refuse the Field Sobriety Test
The police officer will ask you to do 1) Follow their pen or light, 2) Do a one leg stand, & 3) Perform a walk and turn test. You have the right to refuse any and all of these tests. These tests are designed for failure. If you trip, slip or lose your balance, that will be used against you.
Hire an Attorney
Once you have refused all of the above, it will be essential that you hire an attorney so that you can fight your case.