High-weekends off
High-Mondays off
Medium- high productivity per duty period
Medium- days off
Low- avoid deadheads
Low- avoid sits longer than 3 hours

I typically get 18 or more days off 75-80 hours block, and all weekends and Mondays (wife's off day) each month. The work combo is a week off and 3 weeks of 4-day trips, or a combo of some 2/3/4 days trips I equal 12 days working in a normal month.