Basically I simple don't use local variables until I check that they are right, then I add some breakpoints into the areas I think is going to fail, Or where I am specting certain return, in that phase I use the inspection feature of vlisp or in the command line the !
The functions are saved into modules and every module is inside of a folder with the same name, I use PRJ projects and if one module is needed is simple added.
All the new functions are saved into their category if they don't fit in any existing then a new module is created.
Luis.