Picking up a GS
Firstly, they don't usually fall all the way over, the cylinders stop that.
But if the cylinder is in a hole or a rut, yeah, thats fun
If it has fallen on to its RHS (Right Hand Side), put the side stand down so when you lift it up, you have some thing to lower it on to and doesnt fall over all the way to the other side. Next, turn the bars so the front wheel is point to the left. Hard up against the stop. This will stop the bars turning when you lift it, because they are hard against the stop.
Then, back straight, legs bent, squat under the right hand bar grip, both hands, and lift, one easy smooth lift. Get it upright, get control of it, both hands on the grips etc. If the side stand is still down, and the ground stable etcetera, you could ease it over on to the side stand, or hold it there and mount the contraption. Yes, from the RHS, because you practiced that already, yes?
If it has fallen on the LHS its the same, except no side stand.
Simples.
That is on a good firm surface, like a car park or traffic lights. Other surfaces are the same process, just variations on that.
For laying it down, as you would do to practice picking it up, its the same as above, just lowering it instead of lifting.
Others will likely have different techniques or points to add.
The above works, Ms Hay Ewe can do the above with her 310GS. Being on the shorter side of the tape measure, her difficulty is the height of the whole bike, but she can lift it up to vertical following the above way I taught her.