If more detail is needed we can add that later.
So do I use my rear brake?? As we all like pics....this one isn't that good but yeah I use them from time to time.....

The most common thing I hear about the rear brake is " I could take it off and never know it was gone" which actually is true around 90% of the time.
Like I referred to it in another thread, the rear brake is kind of like a "special" tool, one that lives in the toolbox and rarely sees the light of day but when you need it, at times nothing else will do.
I'll break this up into 3 sections, first the most common use of the rear brake. Then some of the "advanced" times when it should or can be used and finally set up
The most common place to use the rear brake is in two up riding. The reason for this is by adding weight to the rear of the bike ( so this applies to a bike loaded down for a weekend trip also) you have not only made the bike heavier, you have also moved the CG to the rear. Also it just tends to give a smoother ride to your passenger with less chance of the "head banging" especially if they are new to riding pillion.-
Which now shifts the weight bias to the rear. This will become even more apparent if you are going uphill or are on a slick surface. So in many cases, while two up or heavily loaded, the rear brake can have as much or more stopping power than the front.
So while two up I try to teach the old method of 60% front -40% rear at all times but always be ready to shift those percentages as traction allows. The one thing I suggest different than some of the old way of teaching is to apply the rear first and then the front. This is to first start transferring weight to the front end before you start braking with it.
This will also get you used to the "feel" of the rear brake which will be important for the next couple of uses.
These next ones are what I call "Advanced" uses of the rear brake. I call them that because done wrong you can\will crash. As this is for everyone, in case you never heard it or don't know...... On a motorbike, loose the front end = low side...... Loose the rear end = high side. This isn't 100% true but close enough to take it to heart as these are things, that done wrong, can cause you to loose the rear.
That is why it is a "special" tool, just like you wouldn't use your digital calipers to loosen a bolt, there is a time and place for it.
With that here we go.
This is where I use my rear the most, tightening you line in a corner.
Picture yourself going down the road and rolling the bike into a corner. Now you see something in your line you want to avoid and the easiest way around it would be to turn a bit tighter.
You could shift your body weight. You also could add a bit of counter steering but both of these have the downside of it is very easy to unsettle the chassis by moving weight around while leaned over..... so the answer move your toe over and drag a touch of rear brake. You line will tighten instantly with the least amount of chassis movement.
This is also a good thing to know if you get into a corner too hot and can't lean anymore but still need to turn tighter.
You will need to work up to this and the best way to get your first "feel" of it is either on an empty clean road or an open car park.
It is usually easier trying in a left hand turn first, as it keeps your braking foot on the high side.
With a comfortable lean angle (it doesn't have to be tight, just leaned over a bit) and feed in a little rear brake. You will feel your turn tighten instantly.
What you need to learn is the "feel" of the rear brake and develop the muscle memory to use it. Kind of like you needed to learn the "feel" of your front brakes before the first time you really used them....or at least you should have.

Another place the rear can save you is if the chassis gets unsettled. The best example I can give you is we have all seen races where someone comes out of a corner a little too hard and you see the bike try to tie itself into a knot.....then just straighten out and continue on its way. Well we know the chopping the throttle usually just makes things worse in these situations and the bike only slowed slightly, so what happened?
In most cases a touch of rear brake is all that is needed and the bike settles right down. This is advanced as to do it right it has to be almost instinctual, so you have to be used to using the rear brake and you also need the muscle memory to use it correctly but it really can save your ass..... just like a touch of rear brake can bring the front end back down if you lofted the wheelie a bit too high.....
Which then leads to set up. The most common issue here, that I hear, is there is no feel in the rear or it just locks up.
I was right there with you when I decided I was really going to learn how to use the rear brake around 10-11 years ago.
I was actually kind of frustrated and could not figure out why I was having such a hard time with it.
How does this have anything to do with set up you ask?
Well I was sitting there looking at the bike, thinking I can walk and chew gum at the same time....why can't I do this?
I start thinking is it my chassis set up and going down a couple different paths, when the little light turned on.....
So Spanky...... you are locking up the rear wheel everything you try to use the brake...so why are you running a high bite HH pad?
Well I don't know Wally......

Went down and picked up an organic GG rear pad set and it's been all good. I can still lock the rear wheel but it takes effort and transforms the rear brake into something you can use....it really is that easy

Before you ask which rear pad I am using... I really don't remember. The fronts I will only use one kind....maybe another good topic...... but the rear any organic pad will work (as long as it is a name brand..... never go "cheap" when it come to brakes IMHO)
Think that is it for now.....