Great way is to make bitcoin with bitcoin that is trading and renting on trading and exchage sites like yobit and polonix which i use personally i recomend you. but i am not responsible for your investment.
Supposedly if you advise someone to do trades you also have to accompany the tips and tricks on trade. It will show your responsibility. Otherwise that guy will potentially lose money in vain, trading need the experience in predicting fluctuations graph.
I agree with you as only advising some for trade will not be better for him because he will not know how to start trade and will lose his money if we have to advise someone for trade then we also have to tell them how to trade or we have to show them for place where he/she can learn about trade.
Tell him also the risk of trading not just the good parts of it. Trading is very unpredictable. Even some pros still lose from it. They just manage to recover it quickly because of their wide knowledge about trading. Yes, trading really gives you some good amount of profit but if you can't accept the risk of it and blame somebody who introduce you in trading because you lose then it is better to not try it at all.