What precautions should travelers take regarding their passports and visa stamps before crossing borders?

I'm surprised. You travel around the world, you know you need a passport and a Visa for certain countries, you obviously know how to apply for the needed visa but you never check if you collect your passport, So I read now several people who did not know there is an extra stamp next to their visa, I read there are people who did not know the passport had no empty pages. I read people who forget entry stamps or got the wrong entry stamps and all come with the question What to do. Easiest thing is CHECK YOUR PASSPORT even before you decide to cross a border and check what the Immigration did with the passport, check the stamps and check the dates and free pages and TAKE CARE the only document that allows you to travel around the world.