Step 1: What you need
1m of 50mm nylon webbing.
1.5m of 40mm nylon webbing.
(quite easy to adapt to different widths of webbing, but that's what I happened to have around)
Thick black thread, synthetic if possible.
2 x toe clip straps, such as these from Zefal
2 x 4.5mm x 200mm cable ties.
The attached layout file, printed out if possible:
Step 2: Cut webbing to shape
Seal all ends by melting with a flame to prevent fraying.
Step 3: Sew together
Step 4: Sew the loops
Pin as shown in the picture first and again, do two passes for toughness. Tie off well.