alt Hacker NewsI'm doubtful there's a universal best way to learn a new language. Part of learning a new language is learning how to learn a new language - what works and what doesn't for you.
For me, doing something everyday[Duolingo], and one on one tutorial instruction[1] have had the biggest payoff. The first for rote memorization, vocab, and exposure to grammar. The second for listening, speaking, and filling in grammar gaps. For Americans, the price of international individual instruction is surprisingly inexpensive due to the dollar being the reserve currency. That translates to about €135/month for to learn French. The workload and cost are both sustainable and my weekly session has become one of my most looked forward to things I do each week.