How can we design digital artefacts to help young adults with low self-esteem feel happier? To gain new insights into young adult's self-esteem problems and how we might help support them with interactive technologies, we conducted a mixed method user-centred study. We used a 6-week cultural probe study with 11 young adults, including a focus group, to understand current practices in managing self-esteem with everyday technologies. We then co-designed interactive digital artefacts for helping improve self-esteem, to deploy as technology probes with 6 young adults for four weeks. Our contribution is twofold. Firstly, we present the Self-Esteem Technology Support (SETS) framework for informing design of interactive technologies supporting young adults in managing low self-esteem. Secondly, we propose that interactive technologies designed to help young people feel happier need to be flexible, adaptable, private, available, personalisable, and have an engaging form factor to inspire feelings of fondness toward having the device as part of their daily routines.