I'll see if I can describe this thoroughly.
- I usually start my shoes off by modeling out the sole from a box and I'll do this while following an image plane of the bottom of the shoe.
- The top part of the shoe I'll begin with two separate boxes (one for the back and one box for the front) as I start shaping these boxes eventually I have them merge somewhere in the middle.
- Once I have a nice shape for the top part of the shoe I will use the step build tool in max to build layers of separate panels on top and then create an intruded edge along all sides for placing stitches onto later.
- for stitches here is a great tutorial:
(also when it comes to adding detail I've found that its ok not to guide loops through out your model depending on how flat the surface is. subdividing it will quad everything off anyway.)
Sometimes by guiding loops all the way through your model you start to add some pinching to places where you once had even edges.
Hope you find that useful!