I have a 7/8 punch
But I don't use it for bottle caps. I use it for glass domes. I only use Colores on bottle caps and I can do about 250 at a time. That's how many I can fit in my oven or I would do more!
Your tips are great, but even if we told someone exactly how we do it, they would still have to go through their own trial and error to get them just right.