Many younger workers don’t sign up for their 401(k) because the process feels too overwhelming. The last thing you want to do is add to the confusion by launching into a long lecture on asset allocation. A better tack, says Brigitte Madrian, a Harvard economist who studies the behavior of 401(k) participants, “is to break up the process into smaller pieces.”

Your first goal: Encourage them to contribute enough to get the employer match, without worrying about sorting through all the investment options. Just have them stick the money in a target retirement fund (or if that’s not an option, a stock-index fund).

You can talk to them later about boosting their contribution and fine-tuning their strategy.