How would you compliment someone on their cooking skills politely?

How would you compliment someone on their photography without being inappropriate?

"Your photos are good, but I've seen better." 

How would you compliment someone on their work presentation without being inappropriate?

 "You did better than I expected, considering you're usually not very good at this." 

How would you compliment someone on their artistic talent respectfully?

How would you compliment someone on their outfit without being creepy?