The first surface you grind and polish will be full of misgivings about what you are doing. After you have done that first surface you will pretty much know what is happening for much of the work and it will quickly become easy, routine thing to do. The only problems you will have after that are the actual figuring of a surface which is always an interesting set of problems. Real failures are only in the actual fracture of a piece of glass into several large parts nomatter what else you do to the glass. Go have fun!