Keeping your opponents guessing is always a good idea. The beauty of playing second-hand low is that it gives your opponents less information as to what cards you hold. Once a top card is played, it promotes the card under it. This information is especially important to someone that is naming trump with a weak hand.
In this example, the dealer is in the West position. The South seat determines the best move would be to pass as they have a chance at a euchre if dealer picks the card plus a good bid in next if they don't. West passes as does North. The dealer picks the ace and discards the queen of diamonds. This leaves him two suited with three trump.
South leads the ace of diamonds. West follows suit with the king. North also follows with the 10. The maker(W) trumps with the 9 of spades.
Next the maker(W) leads back the queen of spades (trump) we'll talk more about this lead latter. South plays 2nd low using the 10 of spades. East takes the trick with the left and North plays the king of spade. Five trump have been played. The bidding team now have two tricks in. One more trick needed for the point.
West plays the king of clubs, North follows suit with the 9. The maker(W) throws off the 9 of hearts and South takes the trick with the ace of clubs. He knows he has the top trump and there is only the ace of trump left, and that's in the dealer's hand. He also thinks his jack of diamonds could be boss as West played the king on the first diamond lead. He leads back the right and they collect two points for the euchre.
The interesting thing about this hand is that if they had read my article on playing the three trump two-suited hand, East/West may have been able to make a point. Let's say that after taking the first trick the maker lead back the 9 of hearts instead of the trump. South would most likely have thrown off the jack of diamonds and North would have taken the trick with the ace. About the only way they would have been euchred is if the third seat led back the king of trump.