Pain Reassessment tips needed

Pain reassessment is a big issue at out hospital right now (we are under the microscope from previous poor reassessment charting percentages). Anyone have any great tips on reassessment especially through change of shift? Any great ways to motivate nurses to consistantly do this? We are a Postpartum unit with 4 couplets (8 charts) which I think may be part of the problem due to so many charts to be in/out of all the time.