By knowing your skills and using them appropriately, devising your own plan of attack?

You don’t actually need a macro to craft. What you need is to know what skills you need to use to get the result you want (typically, 100% HQ from nothing). Also ... you don’t need to use a macro to follow it. In a sense, if you know what it takes to 100% a craft, and you do it by hand a bunch of times the exact same way each time, you are following a macro written into your muscle memory rather than into the game.