Ok, so I've been doing a fair bit of pissing, and moaning about issues with SKS, and asking for help on numerous occasions. So today I'd like to talk about something positive. Let's talk about glyphs in SKS, and why I appreciate them so much.
Ever had an issue with an image you just can't solve because there's no stretchable/tilable spots for the margins to deal with? Ever had an image you just made, and love, but it gets mangled because it's round? Enter the use of glyphs as replacements for static, (size doesn't change) images!
Let's take a start menu shutdown button. Let's make it round, say a circle glass button. Now we make it with total absence of memory that it'll have to be put the the margins meatgrinder. The image is perfect, and you can't wait to drop it in the skin, and test it! So you rub your sweaty skinner hands together, and laugh with maniacal glee as you select the image to be imported, and click the apply skin button.
But wait! You open the start menu, and your beautiful new button looks like it's been through the taffy machine at Disneyland! NOOOOO, how could this be?! My lovely button is disfigured! Then you remember margins. "I GOT IT! I'll just push the margins to the far right, and bottom past the image, and it HAS to stay in shape right? WROOOONG. You test again, and lo, it's not distorted, but now it's way to the left, and up away from where it should be! DAMNIT!
This is where a glyph comes into play. Even if the image has a corresponding glyph you can still use one as the main image. All you need to do is "edit" the original image by making am "empty" magic pink image out of it, and use the main image as a glyph!
This image is technically two parts, and both are glyphs because the image was not margin-friendly. You must keep in mind that these magnificent beauties known as glyphs won't work all the time though. Remember, "with great power comes great responsibility!" The image can NOT be sizable IE: say, a push button. Push buttons will change size based on their function. Because glyphs aren't able to change size you'd see some truly nightmarish results.
Here's another example of an image being replaced with a glyph in the start menu.

Now I'm sure tons of people already know about this technique, and use it, but this is for people who've either forgotten about it, or are new, and are wanting to break some rules in order to get what you want.
In closing, thank you for taking this wild ride called glyphs with me, and I hope you all have a wonderful day!