When I hand the stockings each year I have a letter with each one. That is actually how I decided on my itty bitty girl's name. I did her letter and then I was like "okay, that name is the right one." But... It was time to change the monograms the stockings. The letters blended into the silver of the stockings. I was looking for a punch of blue for the mantel.
It was really complicated...
Take plain wooden letters.
Paint them a base color. The glitter might not cover every nook and cranny, so this step is important. You most certainly don't want the wood to show through.
Brush on white glue and cover, and I mean, cover with glitter.
And there you go. Just a little blue to brighten up the silver mantel.