Over the last two decades, lipid nanoparticles (LNPs) have evolved as an effective biocompatible and biodegradable RNA delivery platform in the field of nanomedicine, biotechnology and drug delivery, with the current successes as COVID-19 mRNA vaccines. Therefore, it is important to provide a general workflow of studying RNA-based LNP performance, which further offers useful guidance for researchers who want to work in the RNA-based LNP field. In this perspective, we first summarized the approaches for the preparation of LNPs, followed by the introduction of the key characterization parameters. Then, the in vitro evaluation of LNP performance including cell selection, cell viability, cellular association/uptake, endosomal escape and their efficacy was summarized. Finally, the in vivo assessment in the aspects of animal selection, administration, dosing and safety, and their therapeutic efficacy was discussed. We hope this perspective can offer valuable guidance to researchers who enter the field of RNA-based LNPs and help them understand the crucial parameters that RNA-based LNP demands.