Set aside one day each month for group orientations
This will allow you to make the orientations a bigger deal with more regular senior management involvement. Monthly orientation also facilitates creation of onboarding cohorts.
[This is adapted from Onboarding (Bradt and Vonnegut, Wiley 2009) and expanded in The Total Onboarding Program (Bradt and Bancroft, Wiley/Pfeiffer 2010)]
