I usually send everyone on a 4hr task up until 1pm. Harvest all cash and XP from available buildings; then I'll send Agnes, The Collider, Herman and Sherri & Terri on their 16hr tasks, because I like them (Sprawl-Mart for Agnes over the Clampitheater). Set up Channel 6 and KBBL with their 16hr tasks as well.
I go cold on sending any others on tasks unless if I work (I work a seasonal job at the local minor-league baseball stadium), and as such will go about 10 hours or so without tapping).
If I don't work, I go cold until 5pm, sending all the characters I prefer on their 12hr tasks, on them; characters like Anger Watkins, Jerri Mackleberry, Kathy from Personnel and Wendell Borton to name a few.
If I feel up to it, I'll send the remainder on 8hr tasks, going through them manually.