You should take proper precautions as a matter of course. [=as part of your usual routine]你应该按常规采取适当的预防措施。

We went out to dinner on her birthday, and as a matter of course [=of course, naturally] we paid for her meal.我们出去吃晚饭为她庆祝生日，理所当然地，我们为这顿饭买单。