I adapted Rob Waring’s paper “How to get your students to use their dictionaries effectively” (OUP, 2001) and created a worksheet for my university EFL students to help them become more familiar with the various functions and uses (and limitations) of their dictionary.
Rob Waring stresses that it is best if all students have the same dictionary when you give them this kind of dictionary training. These days, tho, almost every student has one of several types of electronic dictionary, so getting everyone to buy or use the same type is unrealistic.
It takes about 40 minutes to work through the worksheet, though your mileage may vary.
With just a little editing, it could be used as-is for EFL students other than Japanese.