Excellent post and suggestion. Here are a few more things I have riders do when practicing.
Start the braking exercise at 15mph and slowly bump up your speed. You do NOT need to be going fast to get the benefit of the exercise.
Use all FOUR fingers on the brake lever. Under a good firm progressive squeeze, that front brake lever can and WILL travel all the way to the grip. So if you have any lazy fingers that don't wrap around that lever, they will get crushed and the rider will either let go and give up the brakes, or not achieve maximum braking due to lack of lever travel. The LAPD will wash a candidate out of motorschool for failing to use all four fingers during the braking evaluation.
Follow through. By that I mean to continue the above mentioned progressive squeeze of the front lever and progressive press of the brake pedal for at least 3-5 seconds AFTER the bike has come to a complete stop. This builds muscle memory. The human body plays, or rides like it practices, and what we don't realize is that everyday we build some not so good habits. In particular is letting off of the brakes at the last moment. We ALL do it. We do it in our cars and on our bikes. As we approach that stop sign or traffic light we brake, and then without realizing it we let off for a few seconds so we can roll up right to that big painted strip on the road and then stop. What this does is teach our muscles to let off at the last moment when braking. It's a subconscious thing most don't realize they are doing. I see it all the time during braking practice. Riders come down, apply good threshold combination braking, and then let off and roll those last 4-6 feet before reapplying the brakes and coming to a complete stop. When I mention it to them they don't believe they ever let off! By continuing to squeeze for 3-5 seconds after the bike is stopped, the rider builds muscle memory that corrects that habit. That way when an emergency braking situation presents itself there will be no let off.
Down shift to 1st and keep the clutch pulled in. The left foot goes down to hold you up, and the right foot STAYS UP AND ON THE BRAKE PEDAL continuing the progressive press.
When braking keep your right heel DOWN on the peg or floorboard. Do not allow it to rotate up and off the peg or board. If you do you will be standing on the pedal with no way to properly modulate the progressive press.
As with all things in motorcycling, keep your head and eyes up. Don't allow the forward braking motion to tilt your head down or to the side. If you do you will lose the horizon and your balance.
Lastly, make it part of your REGULAR practice. At the end of every class I tell the riders that the ONE skill they should work on regularly is threshold combination braking. It doesn't take much. Once a month find an empty street or parking lot and make 10 passes using the above technique. Work on form and be deliberate in the actions and motions.
And those of you in harsh winter climates who garage the bike for a few months, please take heed. Any former has-been, never-was jock can tell you that our athletic skills perish with lack of usage. So when you break the bike out next spring, spend a weekend bringing your skills back up.
This is what I was taught, and this is what I pass on.