This report is the fourth in a series describing the RAND Corporation's evaluation of the two Delaware weighted funding programs for disadvantaged K-12 schools spanning the 2019-2020 to 2021-2022 school years: Opportunity Funding and the Student Success Block Grant. The authors drew on annual surveys of Delaware local education agencies (LEAs) that received Opportunity Funding and describe investments that the LEAs perceived to be best practices for improving the academic achievement of multilingual learners and students experiencing poverty. The authors also drew on in-depth interviews with staff in three LEAs to share representative examples of how LEAs used Opportunity Funding. [For "Evaluation of Delaware's Opportunity Funding and Student Success Block Grant Programs: Early Implementation," see ED626324. For the "Second Year" report, see ED626325. For the "Third and Final Year" report, see ED626326.]