You’re right about “process”, in that all good designers follow a similar one so there’s no need to talk about it unless you do something very unique. However, that’s on the assumption that the purpose of your portfolio is to get hired (and therefore the people looking at it are familiar with that design process).
If you’re like me (a freelancer), your portfolio is more for potential clients than for potential employers, so the game is different. In that case, some mention of process is not out of place, as it helps set the right client expectations and build confidence that you know what you’re doing.
So the #1 thing for designers to work out is this: what is the goal of my portfolio, and who’s going to be looking at it? Then build the content for that audience.