Buy from a big reputable exchange or buy on localbitcoins. That's the only way to take less risk. In the bitcoin world there is no such thing as no risk.
Yes, to make the best returns you should use localbitcoins or a similar peer to peer trading system. You should be prepared to record every transaction and identify who you are trading with. You might want to split big trades up instead of doing it all in one go. The biggest problem to stay legal in your home country will be making proper records and paying any applicable taxes on your income.