Personally I'd use a box, subdivied across into 3, extrude these one or two divisions to give the 3 toes, then shape them accordingly (taper at the ends, flatten the end slightly etc..), then subdivide across the rear of the foot to allow a tapering rear at the heel, then extrude the rear section upwards to create the ankle / lower leg.
Then, smooth and sculpt any areas that are too blocky.
Then, smooth and sculpt any areas that are too blocky.