Maybe not so much of a tutorial, but details on how I put together a lot of my shoes for costumes.
I usually use pleather shoes for most costumes because I love the way they look! Also, they accept paint easily. So that helps.
There are some awesome options available for painting leather (and faux leather/pleather), but for the longest time I didn’t know about them and I just used acrylic paint and mod podge to color shoes. It’s cheap, readily available, and I could mix pretty much any color I needed so that the shoes would match my costume. Generally two-three coats of paint and one coat of mod podge is enough to cover the whole shoe.
The downside to using acrylic is that it can crack (particularly if you use it on tall boots, or anything which needs to flex a lot when you wear it).
For shoes that have extra straps (like Neptune’s and Uranus’s) I cut pieces of pleather, painted them, and sewed them to the shoes. For Neptune’s I sewed a loop of elastic to one end of the ankle strap and a button to the inside of the shoe that the loop hooks over.
I hope that helps someone! I promise, having the strap on Neptune’s shoe match the rest of the shoe looks a lot nicer than using ribbon, and only takes a little bit more time to add on.
As a final note- there are paints made specifically for changing the color of shoes. Angelus leather paint and Meltonian Nu-Life spray are two that I would absolutely recommend! For any sort of boots, or shoe with a lot of movement the result is going to last longer using those paints rather than acrylic.