If you have a stack of shirts or ties in your suitcase already, just wrap the ties all the way around that bundle. They won't fold back on themselves directly, so no crease will be able to form. Just make sure that the last part of the tie is flat against another shirt/pair of clothing.
If you use a garmet bag, just hang a pair of pants on a hanger, drape your ties over, and throw on another pair of pants.
If you are a carry-on traveller, this will probably take up a lot less room than a tie case.