When interventions target cognitive skills or behaviors, capacities or beliefs, promising impacts at the end of the programs often disappear quickly. Our paper seeks to identify the key features of interventions, as well as the characteristics and environments of the children and adolescents who participate in them, that can be expected to sustain persistently beneficial program impacts. We describe three such processes: skill-building, sustaining environments and foot-in-the-door. We argue that skill-building interventions should target "trifecta" skills -- ones that are malleable, fundamental, and would not have developed eventually in the absence of the intervention. The sustaining environments perspective views the quality of environments subsequent to the completion of the intervention as crucial for sustaining early skill advantages. Successful foot-in-the-door interventions equip a child with the right skills or capacities at the right time to avoid imminent risks (e.g., grade failure or teen drinking) or seize emerging opportunities (e.g., entry into honors classes). These three perspectives generate both complementary and competing hypotheses regarding the nature, timing and targeting of interventions that generate enduring impacts. (author abstract)