The easiest way to add glitter to cards is to use double sided sticky tape as your glitter adhesive.
One of the benefits of using the double sided adhesive tape is that you get these nice stripes of color on your card. You can play with using different widths of tape like I have here.
You can also play around with varying the spacing between the stripes.
I did one stripe at a time to keep the colors separated. I always burnish the glitter with my finger after I pour it on and shake off the excess. That really allows it to adhere and gets the excess off as well.
The bell garland is from the Holiday Borders stamp set, as is the sentiment. I heat set the image and the sentiment in black embossing powder.
My card is finished off with some green Crown Jewel Gems.
Happy holiday crafting!