There is a common tool to use when assessing minimums – the Personal Minimums Checklist. But this is only a mechanism for getting you thinking about what your personal limits should be.
You should definitely have minimums; in fact legally you already have. Beyond these are your personal minimums, which may well be higher (or more restrictive) than the legal minimums. These will be the minimums you use to decide if you are going flying or not. But what do you use when you are airborne and need to make an assessment then? What do you do when you are more or less current than when you decided on those minimums?
Personal minimums should be set on the day of flight and considering the day's circumstances like currency and competency, and not updated in flight unless absolutely critical, ie, to avoid injury.
It’s also not something you should change on a whim, or in response to pressure from passengers, for example.
But there may be times when sticking to your personal minimums doggedly will not be the safest course. And that is the critical factor here – what is the safest course? – it could be that you need to break your personal minimum in order to fly as safely as possible. But that is the key, to fly as safely as possible.
Do not break them just to complete the flight, or to just take a look around the corner, or to please someone else. Your minimums are there for a reason. You have considered them carefully in the cold light of day and when you were not under pressure.
This is why it is so important to practise your risk assessing skills and to keep your situational awareness high. If you can keep your situational awareness high then you will limit your surprises.