I think it helps to do things consistently in ALL your ships, regardless of role.
For example, I ALWAYS put limpets on fire 2 regardles of whether it's a mining ship, a scavving ship or a pirate ship.
That way, I have the muscle-memory that allows me to launch limpets and not have to think about whether or not I'm pushing the correct button.
Equally, I ALWAYS set up my ships with offensive laser-weapons in the first fire-group, lasers+kinetics in the 2nd fire-group and all the various scanners (datalink scanner, composition scanner, surface scanner and disco' scanner) in my last fire-group.
That way, I always know how to navigate through my FG's to get to what I want easily.
Lastly, don't forget that you can allocate more than one thing to a fire button and they don't, necessarily, have to be things that are getting used at the same time.
Obviously you could, for example, allocate lasers+kinetics to one fire button but you can also allocate, say, a frameshift interdictor and collector limpets to the same fire button because they'll never be available for use at the same time.
With all that in mind, I have a variety of mining ships - with a variety of weapons on them - but I try to set them all up in order of how they're used during the mining operation, and what things get used together.
So, for example:-
FG-A: Lasers[1]
FG-B: Lasers+kinetics[1]
FG-C: PWA[1] and Prospector[2]
FG-D: Mining Lasers[1] and Collector[2]
FG-E: Sub-Surface Missile[1] and Collector[2]
FG-F: Abrasion Blaster[1] and Collector[2]
FG-G: Seizmic Launcher[1] and [Collector[2]
FG-H: Composition scanner+surface scanner[1] and Disco scanner+datalink scanner [2]
Obviously, that's for a ship with ALL the mining toys.
If you're using, say, an AspX for deep-core mining it'll be slightly simpler.
FG-A: Lasers[1]
FG-B: PWA[1] and Prospector[2]
FG-C: Abrasion Blaster[1] and Collector[2]
FG-D: Seizmic Launcher[1] and [Collector[2]
FG-E: Composition scanner+surface scanner[1] and Disco scanner+datalink scanner [2]
Notice how even though there's less FGs, everything's still consistent in the way it's ordered, and what stuff is grouped together, so even if I haven't flown a ship for 6 months it won't be confusing.