There aren't too many tips, but I can give a few:
- Try to only milk her once she's full. It'll save you time switching tabs, and you get more milk per percentage when she's larger.
- Carefully look through the upgrades on your completed save to figure out which ones you want and which ones you don't need. All of them are necessary to unlock future upgrades, but the order you get them is mostly your choice.
- Get them goated gamer hands, which means you also have to play with your right hand. I know, I know.
- Possess endless love of Yuri in your heart, for she will see you to victory.