Training instructors will shoot me down for this post because they are going by the book …a very OLD book! Yes there was a time when a clutch and front brake required so much force to apply an entire fist was required, but those days are long gone, unless you are still riding a vintage BSA or similar. Hydraulic actuated clutches and modern disk brakes made the full fisted practice totally obsolete and I challenge any to prove me wrong when I say one finger on each control lever or at the most two is by far the best practice. Even beginners recognize you need at least three fingers and a thumb to maintain a firm grasp on the grips. Training course instructors insist you use all of your fingers to apply the front brake and the clutch and that is just SO wrong. I’ve seen you tube videos of beginners going over the bars and getting kicked out of class simply because they hauled on too much front brake and I hold the instructor totally responsible for such a failure.
Anybody riding at a skilled level in motorcycle competition does not use a full fist of front brake or clutch, so why it is considered a best practice for beginners???
Try riding a Trial with a full fist of lever and your arms will be so pumped and fatigued you won’t survive one loop, except maybe the loop over the handlebars. You can do nose wheelies with one finger on the brake, lock the front wheel going down steep hill or smoke a front tire braking from high speed on a street bike, so why would anyone teach you to use a fist full of front brake???
This is not even me but every picture I have of someone riding advanced Trials clearly shows the same thing, one finger on each lever. (my levers are moved in further on the bars than his)
I ride with one finger on the controls nearly all the time other than going up extreme steep hills or splattering a rock face and the reaction time is a fraction of what it takes to open a full grip from the bars. If your fingers are too weak to pull in your clutch or front brake, exercise your hands more and move the levers in on the bars to give you more leverage where you can.
This first part is important: You will likely need to go through the motions of using their full fist method to pass your training course, but I still maintain it is totally wrong, just don’t argue with the teacher on my account. Personally know 4 motorcycle training instructors to date that I can out ride, so if they disagree; come on out and ride against me in an observed trial competition or challenge me to a slow race 
If anyone can whoop me using a full fist to clutch and brake, I’ll take back everything I said and clean their entire motorcycle with my tooth brush
…engine braking is very important and even more so with a heavy bike, learn it well.
Elsewhere you inquired about servicing; I spend nearly as much time cleaning and servicing my motorcycles as I do riding them.
