Having had a shoe fetish for almost 40 years, I have adapted the use of a high heel shoe into many of my masturbation sessions.
First of all, I am particularly attracted to closed toe classic stiletto pumps. The heels must be at least 4-6 inches to cause arousal. There is something very visual and sexual about this type of shoe. I have always thought that there was something quite phallic about a stiletto high heel.
There are two uses of the high heel that really get me off quite quickly.
The first one is more obvious involves anal penetration with the heel of the shoe. What I usually do is place the heel upside down on a small pillow with the heel sticking up and slowly sit down on the heel until it is completely in my ass. Whether you place the shoe so the front part is against your balls or is against the back of your ass depends on which angle is most comfortable for you. I prefer to have the toe of the shoe against my balls because I can look down and see the pointy part and also can slap my balls against the bottom of the shoe as I masturbate. It doesn't take me long at all to get off.
The second and not so obvious use of the high heel is to put my erect penis into the toe of the shoe. There is something about the shape combined with the friction of the inside of the shoe that makes it feel very much like a vagina. Also your balls are cupped nicely in the arch of the heel. To masturbate, I simply hold onto the underside of the shoe and move it back and forth quickly until I cum inside the toe of the shoe. This is very practical because all of the sperm is contained and is easily to clean up.
My wife has some great shoes that I use on a regular basis. But it is necessary to keep them clean.