I think it helps to have a complete list of rules laid out between you and your subs. Sit down and think about what you want to achieve with your subs. Obviously it has to be fun for them and you but what else do you want? Do you want to improve them in some way - improve fitness, achievement in work, academic achievement, financial stability, dress, behaviour etc? Do you want to turn them into a specific type of slave - servitude, sexual, sissy, etc? Do you want them to make your life easier - doing your DIY, housework, filling out your tax forms, giving you relaxing massages etc?

Sit down and work out a number of objectives based on what you want, what they want and what you think they can achieve. These objectives may change with time but laying them out formally helps organise your thoughts.

Then you work on rules that fit those objectives. For example, if you want to make your sub a sissy sub then you need to start thinking of things that will encourage that. Such as: Only peeing sitting down, exercises to tone the waist, periods when they have to dress in sissy clothes, what female underwear they have to wear under their male clothes and when. If you want them to be a service slave then you need to consider what household tasks they do and when and how well. You then punish any transgression of these rules with, as Den says, a punishment that fits the crime.

As they progress as a sub, you may change the objectives and the rules. For example, if you think they are finding wearing female underwear under normal clothes too easy you may decide to add a rule requiring one piece of feminine clothing or make up to be worn overtly (i.e. a blouse instead of a shirt, a feminine neckscarf and so on).