Write it Down

Document design decisions and parameter limits as they are incorporated into the design.

Developers make decisions every day regarding how to meet the requirements they have been given.  Most of those decisions seem to be small and inconsequential when being made but can cause significant issues or ripple effects later.  Documenting those decisions as they are being made and then sharing them with others can raise the level of awareness and, perhaps, save significant time and effort in the future.