I am going to start a new topic on selection, preparing care and use of dive masks.

My contribution is brands can be like boots, find the brand that fits your face and purchase several at the same time.

There is no rhyme or reason, I find an inexpensive brand, Promate, fits me to a tee.  They are like 20 buck masks on Amazon if you shop right.  http://www.promateusa.com/masks.php

My other tip is I don't care how loose you have your mask strap, it should be as absolutely loose as you can get it, the pressure will push it against your skin.  This is a counter-intuitive thing.

The pressure will seal it.  The number one mistake I see is people over-tightening the strap and distorting the skirt and thereby causing leaks, the imprint of the mask post-diving and soreness on the bridge of your nose.

I have found you can set these things stupid-lose and they will seal and work just fine..

Preparation:

Unless your mask is prescription, or has a special coating (in which case, follow the provided instructions), I put a small amount of toothpaste on the inside of the lenses and polish using swirling motions with my index finger.  Best done while watching TV.

After a few minutes, I rinse and then clean with blue dawn dishwashing detergent.

The point is to get the release oil and debris off the inside of the glass to create a clean surface.

Before diving, I smear a small amount of sea drops and do two quick rinses before I don my mask at entry.

In water, I use spit.

Occasionally, re-clean with the blue dawn.

Use:

I place the strap directly behind the mask.  Should I encounter a persistent fog, I deform the seal with my finger and allow a small amount of water to enter.  There I swish as necessary to remove the fog.

My one big trick is when doing a full clear, angle your head and direct the exhaust from your regulator as you lift out on the bottom of the skirt.  This can help clear a larger volume on your first exhalation.  With practice, you can almost completely clear a fully-flooded mask through exhaust and by venting your nostrils at the same time on the first go.

You are only trying to remove a bit of silicone residue.  It’s not on there that hard.