I recently started working with someone who throws around a lot of light praise to others, such as "good job on that!" "nice work" or "keep it up". He seems sincere but it struck me as a drop funny because he'll say it to anyone regardless of the levels/relationship. For example, he'll say this to junior peers, senior peers, external consultants (staff aug type of consultants), and even to the lead developer on the team (who has 10 more years of experience than this fellow).
On one hand, it can easily be viewed as patronizing or insincere, but everyone also likes to know that their work is appreciated/recognized.
From an objective perspective, what's the best way to praise other people's work without sounding patronizing or insincere? Is there such a thing as "too much" praise, or levels/relationships where praise is inappropriate (like to the lead developer)?