Lionel Messi acknowledged that his disappointing record from the penalty spot is something he must continue to work on.
Messi, 31, missed four of the eight penalties he took last season for club and country, including one against Iceland for Argentina at the World Cup.
In total, he has missed 24 penalties during his career, and he even handed spot-kick duties to Luis Suarez in Barcelona's win over Huesca before the international break despite being one goal away from a hat trick.
"I would like to be more effective from the penalty spot," Messi told Catalunya Radio. "But it's difficult to work on penalties. It's not the same taking them in training as it is in a game. You can have an idea in your head or something you have worked on, but it's more difficult than it seems.
"The goalkeeper has a lot to do with it, too. If they guess right, they save it. But it's obvious that I'd like to get better at taking penalties."
However, while Messi has struggled from 12 yards in recent years, other areas of his game have improved.
Dropping into a deeper role, he created 12 goals -- more than anyone else in La Liga last season -- and has scored seven goals from direct free kicks in 2018, more than any other player in the league.
"I'm most proud of how my final pass has improved," he said. "In the last year, I think I have developed a lot when it's come to setting up chances, whether they've ended up in goals or not. In that sense, I have grown a lot.
"I've also improved at taking free kicks a lot, even with my right foot. I am always trying to learn and improve every day."
Messi, who has played as a winger and a false nine in the past, said he is happiest in the position he is now in -- starting on the right but dropping deeper to get on the ball.
"It's normal that your game evolves," he said. "When I made my debut I was 17. I played in a different position and in a different way back then. Football has changed since, as has my way of playing and moving around the pitch.
"I like where I play now the most. Teams sit deep and put a lot of people in the middle, so it's easier getting the ball a little deeper and coming inside from further out. Moving to the wing means that a lot of the time, the full-back doesn't know what they're meant to do. In the middle, it's harder to get the ball, because there are fewer spaces and a lot of bodies."