Here is how, in his own words...
-- Quality over quantity. You don't need to "tweet" quite so much. You don't need to be at countless rallies and photo ops. Instead, seek out substantive platforms where you can relate to people in a thoughtful, measured way. Appear on Sunday shows every now and then, sit down with Charlie Rose and editorial boards, and give serious speeches on your approach to the world in the 21st century.
-- Hope and fear. To be elected president, a candidate has to understand voters' fears but appeal to their hopes. Ronald Reagan (and Bill Clinton) knew this very well. To do this more comprehensively, I would suggest traveling more to better get a handle on where the voters are on topics related to finances, faith, race, etc. Get out of the bubble of high-profile events. Go to the inner cities, the suburbs and small towns where folks are trying to live their lives through great anxiety. And don't go to talk about yourself, but to listen to others.
-- Reagan is the past. While Reagan is a beloved president who did much for this country, folks want to look to the future and believe in a new brand of leader. Espousing the values Reagan spoke to and represented is fine, but you need to be yourself, not an acolyte for a president who is now in the history books.
-- Use humor. In responding to controversy, bad press and negative occurrences in general, learn to let it slide off of you with a knowing smile. Maybe even use some self-deprecation. Levi Johnston, your almost son-in-law, has been a thorn in your side. Let it go. Publicly sparring with a teenager is not presidential. Don't be afraid to make fun of yourself. Voters like candidates who know that they aren't perfect and can laugh at themselves.