My suggestion, it to be wearing a very short skirt, a bright color, maybe pink or blue, red would also work... something super short so it is easy to see your ass and cock under the skirt.
Also some lipstick and I'd say eye shadow too except that wouldn't matter if your face isn't exposed... maybe some kind of veil and dark-sunglasses if you have them.

Maybe start by sucking on a dildo, showing how good you can suck cock, (assuming you can show your lips and mouth, and not expose the rest of your face) after a short period of sucking that dildo, (or skip the dildo section if that is too much like exposing your face) spread your legs, with a pillow or blanket under your lower back to help prop your self up, expose everything including your ass, and take that dildo in the ass like a sweet sexy slut.

While getting fucked in the ass by the dildo, let your magic wand hang above you, and get into a position so it can stimulate your erect cock.
Make contact with your cock, stimulate yourself with the wand while taking the dildo in the ass...
and continue, struggle with it, try and make yourself cum... keep going until it your mistress wants you to stop, or perhaps until you cum all over yourself. (if your mistress allows for that part)
After sometime, IF the magic wand hasn't gotten you off, and if mistress allows, finish off by stoking your cock, or pull down the magic wand and hold it to your cock.

Once done, if you've cum on yourself, perhaps all over your stomach, rub your fingers though the cum and then lick the cum from your fingers.
(How graphic you get in this part might depend if you can expose your mouth, and not consider your face exposed)

As a bonus maybe do this while handcuffed, considering all of the above, it maybe be too much to do with your hands cuffed behind your back, but perhaps with your hands cuffed in front.