To crash the glyph market is to drive the price down so low that nobody wants to work the market. There are 2 ways to normaly do this. Post everything at a set price or deep undercutting. The lower you can go the better your results will be. But is its important that you must be getting your mats cheaper then your competition.
If your set price is dirt cheap and most glyphs sell for huge mark up, you will find your competition buying out to relist. I never do it this way. You would need to camp the AH and quickly replace any that got sold. This way only realy works if they undercut you or you have 100% uptime and prevent them from getting sales. I find that hard to do for any normal player.
The other way is deep undercuts. If your competition reposts several times a day, this will work wonders. If you undercut 1G every time you post, then the harder the two of you work then the faster the prices fall. If you post 5 times a day at 1G undercut, after 10 days even the most profitable glyph is dirt cheap.
If you are willing to crash the market, you need to be willing to survive of minimal profits. I would not post at a loss but I can go very low. This is why you need dirt cheap mats. If you move the market down to where profit is minimal, then the lower you can drive your costs the better. So be very careful if you go after someone that already controls the market.
Most of the time I do not crash the market. Someone else does that for me and I have more reserves and cheaper ink than any of them. I do run with a high undercut so when competition pickes up, it naturaly lowers the price for me.