.if you want to use a credit card to pay for something, ask yourself, "could I pay for this with cash?" If the answer is no, think again about actually buying it. On the investment side of life, trust your gut about understanding the investment. I mean if you have doubts be sure to learn a little more before going for it....although if you have someone who you trust, who does it for a living, that is good. Like dental work should be done by a dentist, investment work should be done by a professional.