This brief is the second of three briefs that aim to support future evaluations in the field of two-generation approaches. This second brief highlights the experiences of the four initiatives participating in NS2G to demonstrate how practitioners of other two-generation initiatives can use research techniques to strengthen the implementation of their initiative before evaluating program effectiveness. This brief is intended for practitioners who provide two-generation services and seek to strengthen their initiative using formative evaluation, as well as their evaluation partners. Appendix A in this brief includes a tool designed to help practitioners (1) identify a key implementation challenge related to delivering services to achieve outcomes for children, primary caregivers, and families, and (2) develop solutions to address the challenge. (author abstract)