"GPS units and topo maps for everyone in the group may not be practical"
A basic Garmin Geko 101 and the yellow Garmin eTrex cost well under $100 these days. The Geko 202 costs just over $100.
A USGS 7.5 minute topo map costs only $6 from USGS.
A Suunto M-3 compass with adjustable declination costs only $20.
Combined GPS & compass weight is only 4.7 oz.
Ask the person who got lost if she'd have been willing to pay $126 to know exactly where she was AND how to get to the parking lot on her own.