Although less common, there will be those three trump two suited hands that have an off-suit ace as part of the non-trump set. Be sure to watch for these as the ace changes the way in which the hand must be played.
The dealer sits in South and has turned up the ace of diamonds. Bidding is passed around and the dealer(S) picks up the ace. Some of you may think about passing, then calling alone in spades when it comes back. However, unless you're playing against a group of very timid bidders, the chances are slim that it's going to get back to you. Another thing to keep in mind is the real possibility that your opponents may try a lone call in hearts.
West seat starts the hand by lead the 9 of club. North follows suit with the king and East plays the ace. The dealer /maker(S) trumps in with the 10 of diamonds. One trump is gone and the bidding team has their first trick.
Now here's where we start to see the difference. Instead of leading the smaller off-suit, your second play would be to lead the middle trump, the king of diamonds. What we are trying to do is take out a round of trump. Maybe even get one or both of the bowers to fall. We are trying to give our ace of spades the best chance of surviving. This lead will also leave us with one trump and a way back into the hand if needed.
The maker(S) leads the king of diamonds. West correctly plays second-hand low and ducks under with the trump 9. North is void in trump and throws off a nine of spades. East plays the queen of trump. Two tricks secure with four trump played.
OK, you now know that five trump have been played, and there is still one in your hand. This leaves a possible two trump in the wild. You're already sure that your partner doesn't have them. It's time to go fishing and see who does.
Here is where you lead your off-suit ace. With this lead, you are hoping for one of two things to happen. Either your ace will fly, or it will draw out a trump, allowing you to trump back in for your third trick. In this case, West trumps your lead with the left.
This is perfect because now you have the last play on the next trick. In addition, one more trump is out of play. With the East seat in the lead, even if the remaining trump were out, you would still make your point. About the only way you could be euchred is if West has both bowers (waiting to call next), and leads the second bower back.
West leads back the 10 of hearts, North and East follow suit. Now it's time to make your last trump good. This gives you the needed third trick and your point.
The primary difference between the two different types of hands is that with an off-suit ace you are going to lead trump on the second trick. If you don't have that off-suit ace, then you would lead the smaller of the off-suit cards. From that point, you would have to evaluate the cards that have been played along with what is left in your hand. This should give you the information needed to play the last couple of tricks. Just be sure to start the hand correctly.