I think the first question needs to be, are you someone who likes to emphasize the sweet in sweet potatoes (e.g. add orange juice, brown sugar, or spices like cinnamon), or to make them more savory. We prefer savory so we are doing this:
https://cookieandkate.com/savory-mashed-sweet-potatoes/
and fries, because the kids love fries.
Both are things I make during the year, but they are good.
If you want fancy, what about hasselback? Can be done sweet or savory and they look very impressive!