7″ Ring:
You can use the measurement rings on a silicone mat to form your scones into a 7″ ring before dividing them into individual scones. Or you can use any 7″ ring to do the same. This could be the ring of a 7″ spingform cake pan or a 7 inch cake ring.

Because I make scones several times a week, I use a 7 inch cake ring [affiliate link*] I found on Amazon.com. It makes it much easier to form the dough into a perfect 7″ circle before dividing the dough into 8 perfectly formed scones.
8″ Ring:
After you have rolled out thing layers of toppings for the scones, like buttercream or marzipan, you can cut them into an 8″ circle by using the measurement rings on a silicone mat, an 8″ cake board as a guide, or an 8 inch cutting ring [affiliate link*]. You then can divide them into 8 sections and lift each section onto a scone.
*Seasons of Scones is a participant in the Amazon Services LLC Associates Program, an affiliate advertising program designed to provide a means for sties to earn advertising fees by advertising and linking to Amazon.com As an Amazon Associate, Seasons of Scones earns from qualifying purchases.