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Know your fund management company
Before investing in any fund house , you need to understand nature of the company. Every company or fund house has its own way to handle funds. Few companies generally invest in high risk sectors which in turn means higher risk for you too but because they are professional and they continuously keeps analyzing market hence it does not mean they are taking risk without any base. Generally their risk factors are precalculated so you can safely invest in them if you can take risk. Mostly, higher risk gives you higher returns as compared to other safer bets.
Likewise, there are companies who boasts about their star fund manager and mostly bet on them. However, it is all upto you to decide to go with them or not. On the other hand, few fund houses / companies emphasis more on safer and diversified sectors thus minimizing the risk. There also fund houses exploring those sectors who looks promising in future yet no other fund manager may have noticed it.
Hence, in brief above are the ways Mutul Funds are invested by various fund houses. So, again as per your requirement, you may select the type of house you should go with. Generally it is advised to go with diversified mutual funds so that you can have almost guaranteed returns.
Now, further we will talk about the previous performance of the fund house.