Before starting a latrine building programme, consult the users: what are their practices, preferences, minimum distance between men's and women's toilets, vulnerable people's needs, children and babies' needs, menstrual hygiene management needs, siting constraints.
Change both the design of the latrine, and the sanitation programme, and keep changing it as the programme continues. Consider lighting, door locks, accessibility, privacy, wall height, wall material, doors, male/female segregation, screens, adaptations for the disabled and elderly, child-specific latrines, sanitary pad reuse/drying or disposal facilities, handwashing facilities and handwashing motivators.
Have a system in place for gathering feedback whilst the latrine is in use, and for ongoing repairs - particularly if the latrine is made of plastic sheeting. How will the latrines be kept clean, and how will they be desludged or replaced?
The original research which led to Sani Tweaks was "Shining a Light: How lighting in or around sanitation facilities affects the risk of gender-based violence in camps". There is also a blog post outlining the key findings: "We must do more to make emergency sanitation safer".