I know this is old forum but I also have same problems and want answer. If you are there and any other can answer. I am beginner so and you say that use same technique that you are using in box modelling car i can't make box modelling properly so i don't know all techniques of car modeling so can you explain how boot/shoes model create with car modeling techniques .......?
In a way you could apply the same technique as box modelling a car. Get a front and side view reference shot of the boot/shoes like tennis shoes for ankle are look as car. first and then look around on the net for maya car tutorials. Apply the same technique and you should come out with something half decent