The hardest thing to teach someone is confidence. When you go do the interview the interviewer already knows all about your record. The main thing that they are looking for is how does this person think of themselves and can they get a long well with other people.

The thing you want to keep on your mind is that this company is lucky to have the opportunity to interview you out of all the other companies out there.

Do not bring up your 2 failed checkrides unless you are asked about them. If it were me, I would just say that you let your nerves get the best of you. Bring up an unrelated example like a tennis match where you were up 6-1 and the other guy came back and beat you. Joke about it. Than, bring up a "real world" aviation example that shows you are a competent pilot.