The “compliment sandwich” is a bad management technique. It’s taught as way to “soften” negative feedback; you put your corrective statement between two positive ones. But it always just makes the “compliment” part sound backhanded and dismissed while also treating the other person like someone who needs to be babied.
“You’re really nice to the customers, but your sales numbers are terrible and you need to improve them or you’re fired. But cheer up, you’re always on time at least!”
Barf.
If you do want to look for strengths and positives (and you should!), find a way to connect the improvement to the thing you want to compliment them on! Try this:
“You’re so friendly, the customers just love you! I think that’s a great opportunity to bring your sales numbers up too, because everyone always wants to talk to you first. You could really be their guide to our products. Want to practice with me?”
Maybe the sandwich just needs a little dressing, but if you’re just using a compliment to “cover” negative feedback, that’s stale bread.
The Opportunity Machine 