Sand tank experiments in coastal hydrogeology have been widely applied for over 100 years now. They help to visualise and explore variable-density groundwater flow processes, which are typically not directly visible in nature. Laboratory experiments may vary in size, complexity and materials. Three major fields of application for sand tank experiments in coastal hydrogeology may be distinguished: 1) Visualisation and investigation of naturally occurring phenomena and processes: e.g. the influence of subsurface heterogeneities, transport processes within and above the saltwater wedge, impacts by seawater over-wash, as well as tides and resulting recirculation cells. 2) Exploration of human impacts and geo-engineering strategies, e.g. subsurface physical and hydraulic barriers: an overview and bibliometric analysis including a review of mitigation strategies was presented by Kassem et. al (2024). 3) Benchmarking for the validation of numerical variable-density codes: a numerical benchmark of a freshwater lens, including a review, was presented by Stoeckl and Graf (2016). Practical information on planning, conducting and evaluating variable-density sand tank experiments has been summarizes by Stoeckl and Houben (2023). Several prerequisites are essential for the successful outcome of a laboratory experiment, e.g. precalculations of runtimes and materials, scales and (visual) data recording. Aspects like tank constructions, porous media, liquids and tracer dyes also have to be accounted for. The collection of hints and tips may guide novices, as well as experienced researchers, and possibly prevent them from repeating errors that have been encountered during a long history of experimental work conducted.