Ive had some success with a venture capitalist approach. I buy up all the new altcoins that come out for really cheap. most of them dont end up going anywhere but the few that do make enough money to cover my losses plus gain me a couple bitcoins in the wallet. go out there and try new things. only you can decide the best strategy for you
Yes its good to buy multiple coins when the price is really cheap and even if not all but some coins performs well then it will give you good profits and it will also recover your loss of investing in those coins which didn't perform well.