Thanks everyone. I'm almost done, just need to tighten the laces a bit. Would you believe yesterday I spent three hours on the laces alone! I woke up an hour ago and it's now 5am and I'm doing some renders and eating chocolate crocodiles (chocodiles!) I found in the fridge.
Anyway I used a different leather alpha for the texture and I changed the lace eyelets and pull tab, also added ribbing to the sole. The texture for the laces and the stitches is just a pores alpha, which I think I like but I might change.
Things to do, I still need to add a logo to the pull tab, but I can't call them Doc Martens even though they are based on white ladies Docs. I will very likely make the laces a bit thicker and loosen up the pull tab so it doesn't look so stiff.
If I was to be really fussy I should texture the inside of the boot and the edges of the leather parts differently, but here is my progress for now.
A closer shot of the laces and stitches below. BTW, all of this was made in ZBrush starting with a cube primitive for the shoe body and sole, Insert Mesh brushes for the laces and one for the lace holes both of which I made myself.
A tip for fellow ZBrushers: I've found that if I add the stitches as separate geometry instead of sculpting them, it means I can keep them separate on the UV map which makes it much much easier to add and make changes to materials and textures.
Back to bed for the last hours before school