First, go to the computer and find a font that you like. (This can be done in Word or Publisher and I'm sure other programs as well.) View the letter at 100% (this option should be in the top toolbar on your screen). Now, what I do...and it seems a little silly....is hold my cookie cutter up to the screen and see what the letter size will look like on the cookies. If it's not right, go into the font settings and change the letter size.
When the letter is the right size, copy and paste the letter to put several on one sheet and print.
Now time to head to the kitchen. On an upside-down cookie sheet, place your monogram template and top it with a sheet of waxed paper.Using a plain icing tip (I use a #2 or #3, a #1 tip will give a very fragile letter), trace the letters in icing on the wax paper. Continue this process until you have at least double the amount that you will need (you'll see why in a minute). Let these harden on the cookie sheets for at least 24 hours.
Very carefully, use a thin, flexible cookie spatula to slide underneath the letter to loosen and remove onto a plate. Expect to break a fair amount....or at least, I do.After icing the cookies, gently place a letter on the wet flood icing. If it looks off-center, guide it along with a toothpick. Sometimes, you may have to use a broken letter; just piece it together on the cookie and it will probably only be noticeable to you. :)