The published literature on the use of sediment traps has been reviewed and used to validate the conclusions of a theoretical analysis of the physical factors affecting the trapping of particles. Both practical and theoretical considerations lead us to recommend that the 'best' sediment trap for use in limnology is a simple cylinder with a diameter of from 5 to 20 cm and aspect ratio (ratio of length to diameter) of greater than 5 for small lakes and greater than 10 for more turbulent water bodies. We also demonstrate the need to know the approximate particle Reynolds number of particles being collected by sediment traps. A number of considerations lead us to advise against the use of collars, lattices, baffles, lids or reference chambers. Recommendations are made on minimizing the unresolved problem of mineralization of organic material and on optimum length of exposure times, mooring systems, trap holding frames and sample handling.