Praise and Criticism are two important type of feedback given by one person to another. There is a method to giving any feedback. Some views of great people on this subject are:

Sandwich every bit of criticism between two layers of praise. - Mary Kay Ash.

People ask you for criticism, but they only want praise. - William Somerset Maugham.

Praise is as good as the person who renders it. - Cervantes.

Most of us are quick to criticise but slow to praise. We should be just the opposite. - Unknown.

Reprove your friends in secret, praise them openly. - Unknown.