Ecological questions are better addressed by framing multiple working hypotheses and designing sampling to assess their relative merits, often using multiple lines of evidence. Most applications in conservation are likely to differ from ‘pure’ ecology by preferring predictive rather than explanatory approaches. Often the complexity of freshwater ecosystems dictate combining both model- and design-based sampling strategies. Recent developments provide several options to improve ‘standard’ designs. Increasingly accessible geospatial databases have facilitated habitat-based strategies which can improve sampling efficiencies for both standing water bodies and dendritic networks of river systems. Modern organism-centric strategies strongly emphasise estimating detectability of the target species. This helps refine estimates for capture-mark-recapture (CMR) methods and sampling strategies for rare taxa. It also provides the basis for occupancy modelling, which is becoming increasingly popular for broad-scale issues. New technologies in remote sensing, videography, camera trapping, and eDNA will likely further accelerate specialised, more cost-effective sampling strategies.