The Brazilian international, who has scored seven of his eight goals this season from free-kicks, says he spends much of his time on the training paddock perfecting the skill.
"There are some players I always watched, various players who I knew hit the ball well," Willian told UEFA's official website.
"Ronaldinho and David Beckham, they took free-kicks and took them very well, so there are some players I always try to follow and to learn important things from so that I am able to score goals.
"It's an important thing to practice. Training is always important. Not to train too much, but during the day, take four or five shots here and there. That helps you quite a lot in a real match and gives you the chance to score.
"When the time comes in a match it's about concentration, watching the goalkeeper as well, and looking at the posture of the goalkeeper, trying to hit it right."