You want to prevent election fraud, more and more of a problem for Libertarian candidates. Sign waving at busy intersections. Hand shaking by the candidate at the precinct with the heaviest foot traffic. Sign waving and literature distribution at each precinct's polling place, from the appropriate legal distance. Literature drops in targeted precincts.
Telephone calls to all identified supporters.
Precinct walking and literature drops by volunteers. Providing rides to the polls for seniors and other shut-ins. Preventing fraud is done primarily by having an alert poll watcher at each precinct for the entire voting period. Ballot box stuffing with fraudulent votes. This can either be with real voters that the opposition has developed a means to manipulate, or with false registrations, such as dead voters and non-existent voters.