Learning technique has to be priority one.  Taking 10-20 mindless throws isn’t doing any good.  It seems to me the traditional thinking behind throwing is to do it like lifting.  Go in do 2 sets of 5 power throws, 1 set of 5 of another drill, then 2 sets of 10 full throws.  What people don’t seem to understand is that lifting has a built-in overload effect.  Lift heavier weights, and your body compensates by increasing muscle fibers (Strength).  There’s no overload in throwing.  A 16lb shot will always be 16lb. 

The parallel lies between teaching someone a new lift and throwing.  When learning how to do a new lift (like say snatch), usually you’ll use nothing but the bar or even a PVC pipe.    The movement will be practiced repeatedly until you get it.  With a complex lift like snatch some coaches won’t let a lifter put weight on for upwards of a few practices.  They’ll break down the parts of the lift and then work the movement as a whole.  Until the lifter can do the entire lift in a manner that lowers their risk of injury, a responsible coach will not allow them to start loading weight. 

The shot is not that heavy so it doesn't make sense to progress from a baseball all the way to a full-weight shot.  What does make sense is learning how to lift and throw the same way.  Take your time building the form.  Additionally, keep correcting the whole once it’s functioning properly.  There’s no increase or overload in throwing learning the technique is an ongoing process.