I swear by lining pan bottoms with parchment, but cutting a parchment circle every time I bake a cake somehow breaks my flow—and litters the counter with scraps. I refuse to pay too much for precut circles (a pack of 24 circles at 20 cents apiece?!) or buy too many (1000 at a time), even at a great price.
So I cut circles from full rolls of parchment—which I definitely do purchase by the thousand (and maybe you should, too!).
To avoid the irritation of cutting a circle every single time I bake, I occasionally cut a small stack of sheets both 8 and 9-inches in diameter—my most used sizes. Rather than annoyed, this makes me feel efficient. I keep them in an empty cake pan in a drawer—but if you could file them if you have a kitchen file drawer, or put them in a manila envelope, or on a clipboard (so you can hang them inside a cupboard or pantry door). Then, all you need to do is simply reach for one when needed.
To cut circles, stack a few sheets of parchment (on a cutting board if necessary) and set a pan on top. Either run a utility knife around the pan, cutting through the sheets, or draw around the pan with a pencil and use a pair of scissors to cut out the rounds.
A couple of minutes spent doing this every now and then for your main cake sizes lets you jump right into the fun part of baking.