Long Beach and the Salinas Valley joined Bridging the Gap to smooth transitions for students from high school to postsecondary education. Due to policy reforms at the state and system levels, working across systems increasingly became an immediate and practical need for those seeking to improve student transitions from high school to postsecondary education. This brief is intended for those interested in strengthening or developing a cross-system education partnership in their communities. It describes five learnings, or principles of, drawn from the work of the Long Beach and Salinas Valley teams. [The collaborations in Long Beach and the Salinas Valley were implemented through Bridging the Gap (BtG), an initiative funded by The James Irvine Foundation. For a summary on the Bridging the Gap series, see ED597814. For other papers in this series, see "Bridging the Gaps for Students in Long Beach: Cross-System Efforts to Institutionalize Dual Enrollment" (ED597810) and "Bridging the Gaps for Students in the Salinas Valley: Cross-System Efforts to Increase College Readiness" (ED597811).]