I love the optimism of some bridge writers. Sentences like "it is surely not difficult" and "it is clearly obvious" trip off their computer keyboards. They do not realize that for less capable players it is not so clear-cut. (I must have been guilty of this on occasion, but now that I have drawn my attention to it, I will be more careful in future!)
    Look at the North and South hands in the diagram. You blitz into six hearts. West leads the diamond three despite his partner's three-spade opening. How would you plan the play?
    North might have taken the auction more slowly, but six hearts is the best spot.
    The original author stated that it is obvious West's lead must be a singleton. And although I agree with that, I think there are many players who would not win the first trick, if only because they don't see how to make the contract, assuming East has the diamond king and queen.
    The best line is to win with dummy's diamond ace, ruff the spade four in your hand, draw trumps ending on the board, and take the two spades, discarding diamonds from your hand. You know that East started with seven spades, one heart, three diamonds and, therefore, two clubs. So, you play a club to your ace, cash the club king, throwing a diamond from the board, and continue with the club jack. When West covers with his queen, you pitch another diamond from the dummy. On West's club return, you jettison the board's final diamond and ruff in your hand.
    Hardly obvious.