In order for me to design the sandal according to the human feet, I imported a human foot from grabcad.com.

Tutorial

After I imported the foot I sketched with Spline the sole of the sandal.

After sketching the sole, I extruded the sole.

I sketched a vertical line between the two toes and made a pipe out of it.

Here I sketched a circle, extruded it and placed it on the right spot.

I inserted a butterfly image, traced it with Spline and extruded it making a cut. Then I extruded the butterfly again with operation New Body and changed the appearance in Gold.

The diamonds I drag and dropped from a file that I made once, scaled it to the right size and placed it on the corners of the butterfly. I offset the circle too and changed the colour.

I sketched a circle around the ankle with Spline.

Here I extruded the circle. Thes is the strap for the ankle.

For the golden frame around the sole, I offset the sketched sole. Then I split the sole in two and gave the frame the colour Gold. For the engraved logo, I imported my own sketched logo and placed it on the sole. I imported the logo couple of times in different sizes and extruded it with operation Cut.

I split the strap in 5 and changed the appearance of each strap band.

For the strap at the back of the sandal, I sketched a curved line, offset the line and extruded it. Then I moved it to the right place. I know there should be a zipper in order for the foot to go in, but I left it like it this. I leave that to the manufacturer :-D.