Golden rule on financial investment can be an individual decision on what and how to implement such to suit their purpose, but one of it is what you have mentioned, i will like to add to that as well, ensure your investment is on what you're very sure about, don't invest on ordinary thing you just heard and know nothing about, carry your research before making an investment and be fully satisfied with all informations about the investment gotten from different sources, as for me, am not the type that like referral of a thing, I can't vouch on recommending you about something but i may advise you about it, the decision is left to your choice, what works for A might not really work out for B as expected.