Right Click is your friend in this game. Right click on the item you want to Enchant (it can even be equipped while doing this) and choose Enchant. As long as the Glyph you made is of the appropriate level, then you can apply it. This is also how you Charge it with a Soul Gem, if needed.

Note, some Glyphs are only for armor, some for weapons, some for jewelery. And, some enchantments can't be replaced. So, keep that in mind.