If you don't want to spend any real cash I suggest you to start with
free acc cash makers.
My system:
Create double as many accounts as your computer can handle at the same time (example: you can bot 8 chars at the same time with your computer cpu --> make 16 accounts). Then create on each account 2 chars (obviously knights

).
Explanation:
This results in the same amount of bot chars as if you create only x1 accounts and 4 chars per account but in my opinion it is less detectable because cipsoft also checks the account online time (I'm pretty sure they do). If you have 4 knights and you just keep switching the chars then your account will be online 24/7 and also 4x knights on 1 account is like asking CipSoft to instant-delete this account. Also if one account gets deleted, you will just loose 2 chars instead of 4. Only negative aspect that I could think of is that if you want to premmy them up later sometime, you will only get 2 premium knights and thus less stamina = less cash in premium hunting grounds. But as free acc maker this is my personal favourite way.
About Stamina: as they are "just" free acc makers, you don't need to care about them really but still I advise you to not go less than 20h stamina. Maybe you need to find a balance for yourself, it depends how much you care about them getting deleted. Less stamina drain = less detection (from what I know).