We did 2% 10 / net 30. Only moved a few of our clients to pay sooner.
For many of our monthly accounts, we billed at the end of the month for the month completed (Billed for June work on July 1st for example) and then gave them 30 days to pay. So, they were really getting 60 days. Decided to start billing for June work on June 15th and terms due by 10th of following month. (Bill for June on June 15th, paid by July 10th.) This change in the billing date helped much more than offering 2% terms.