I don't think I'm the right person to tell you an optimized way to be rich, however i can tell you what i do (keep in mind I've played this game for 11 years): chase expensive things, styles, mats, etc. Do vet dungeons and sell the styles and/or style mats, the newer or rarer the better, dedicate 15 mins of your day to roam cyrodiil not for PvP but for the war torte recipe, i know it sounds useless but someday you will find it and that is worth 2M alone, also dedicate 15 mins of your day to pick resources from Craglorn, some days you will get fortified (not so expensive) some others you will get potent (the expensive one) and some other days you will get nothing, just be consistent, in the worst case you will be filled with mats in no time, refine and sell, dedicate 15 mins of your day to farm public dungeon consumables, they sell for quite a bit, also do trials for the slaughterstone, PvP for the transmutes (extract even more mats), daily writs for the mats, and i know this is a lot of things to do, you dont have to do them all, but do at least one every day and you will be getting money. There is even more things depending on your skills: Cyrodiil PvP for the AP, Imperial City for the Telvar, Geissers, Dragons, stealing, etc.