The best advice I can give you is to sit down and study some game theory first. Do not try to be all things to all people or your game will be strong with fail.

Read and understand at least two theories such as GEN or The Big Model. Then feel free to decide that what they say is crap and come up with your own ideas.

Players and game designers will always have a spoken or unspoken agenda that they bring to the game, and an inner idea of what a "real" RPG is. Once you know what sort of game you want to write... communicate it!

If a player or gamemaster is able to pick up a rulebook and understand that the game is built to enable and promote a plot heavy style of play with unfair and story driven conflict rules to promote literary tropes, they are much more likely to avoid feeling cheated when they do not get a gritty detailed setting with universal and learnable rules that apply equally to PCs, NPCs and offscreen action.

So, make the Donjons and Dragoons game that drives your passion... but make sure to be clear in telling other people what it is, and what it is not. That way, when a group sits down to play it, they are more likely to appreciate the hard work and criticize it constructively, rather than for failing to meet goals it was never reaching for.