"The best way to do something" 可以用 "the most effective/efficient/optimal method/approach" 来表达。
"Effective" 意为 "能产生效果的"，"efficient" 意为 "高效率的"，"optimal" 意为 "最优的"。"Method" 意为 "方法"，"approach" 意为 "方式"。
例句：
The most effective way to learn a new language is to immerse yourself in it. (最有效学习一门新语言的方法是投入其中。)
The most efficient way to organize your closet is to group similar items together. (整理衣柜最高效的方法是把相似的物品分组。)
The optimal approach to solving this problem is to break it down into smaller parts. (解决这个问题的最佳方法是把它分解成较小的部分。)