Gestures are a preferred mode of interaction for smartwatches and these are commonly elicited either by expert/designers or by users. This paper aims to understand the most promising approach for generating and assessing gestures by employing two empirical studies to validate a set of expert/designer-generated gestures. It further gains insights into the users' mental models, their role as co-creators, and their considerations for one-handed gestures in smartwatches, and discusses the virtue of incorporating both approaches of gesture elicitation.