I don’t know of a miniatures wargamer who hasn’t tried to write his own set of rules. And unless your rules are extraordinarly simple, that means thinking about dice probabilities. Here’s an article on die probabilities with d6s, with a special focus on DBA and Warmaster.
Here’s an interesting bit of advice for printing directly on blank playing cards. It would be useful for better-looking prototype games.
Steve Winter has this article on a new approach to reaction and morale. Inspired by Zulu War games, he tries to move away from the “in command or routing” conditions of other miniature rules sets.