Considering that the market has a ton of shit coins its best to stay away from them and just only way I see any profit making business is by investing in gambling sites bankroll.
Many ICOs are scam and people should be careful before investing in them blindly after reading their tempting offers and giveaways. However many coins are again legit and worth buying only to sell at increased prices and/or mine them and sell them (so you dont pay any money except mining fees).
Investing in casino bankroll is worth it and better for long term and not short term.
What is safe will only offer you a small income, the bigger the risk you take when it succeed the better the return you will get. True, investing in online gambling sites guarantees profit, however it's not that big as we expected because to be able to get a decent return we also need to put up a bigger investment which I think majority of us cannot afford to do it.