When you're giving feedback to someone, give it as close as possible to the action that spurred the feedback. Don't wait for an infrequent time, like a semi-annual or annual performance review. This close-to-real-time feedback will be more valuable if the recipient can directly tie it back to something they did or didn't do. Be direct and focus on specific things that you observed, not on generalities like their attitude. Conclude your feedback by stating what you expect to see in the future. Lastly, avoid the feedback sandwich, where criticism is obscured by layers of praise.