Ultimately, it's only guidance. I used to do DATA, INIT A, INIT B, FPLN, RAD NAV, PROG, PERF, FUEL PRED (ie, INIT B now route data is in), and then SEC. Made a hat shape on the buttons. My brain doesn't work with mnemonics.
At least Airbus offers guidance. The Boeing FMC starts well with prompts leading you through each step and then sort of peters out just as you approach the critical data entry point. I'm always wondering what I've forgotten to do.