A good way to minimize the risks is not invest real money (or invest a little amount).
With some efforts you can earn bitcoin from faucets, forum signature campaigns, glambling (not recomended), trades, etc...
After achieve a good bitcoins amount you could invest It. If you lose all, you don't lose your money.
I agree. Don't invest everything in one project. In this market, the key is diversifying your investment in many different projects so that every other project would serve as contingency with the other projects. We can't foresee the future, so even if you actually study for a venture and see that it has a good chance of prospering, and then after one second, it would go down south, then you would have several other projects to get your investment back. Also, as an investor, it is incumbent to you to study the projects you join, before investing money, every move should be well-researched and at least the risks you took were all but calculated.