The Dutch fought back to draw with Germany last Thursday before Xavi celebrated his first victory as coach when they beat Serbia 2-1 on Sunday.
However, the former Barcelona and Spain midfielder believes there is still plenty to improve.
"It is always most important to get the three points, I'm happy that we managed to do that," Xavi said.
"But we do need to play better because, especially in the first half, we did not press well.
"Nevertheless, I'm very satisfied after a week of work."
Xavi was particularly impressed by AZ Alkmaar striker Mexx Meerdink, who came off the bench against Germany before making his first Netherlands start against Serbia.
Meerdink scored both goals in the victory and earned praise from his manager for his all-round contribution.
"Mexx is a very hard worker who understands how we want to play," Xavi said.
"He helped the team with more than just his goals, although those certainly helped. The work he did for the team was fantastic."
Xavi now wants the Netherlands to become more effective when they have possession and attack space.
"There were many moments when we needed to attack the spaces, but we didn't do it," he said.
"That is something we need to improve. But also things such as making the pitch wider and moving the ball around more quickly."
The Netherlands face Greece in Thessaloniki on Thursday before hosting Serbia in Eindhoven on Sunday.
Despite his concerns, Xavi believes his players are adapting well to his system.
"The most important thing is that we are creating a lot of chances," he said.
"The players feel comfortable on the pitch with the structure we are playing in, so a lot of things are also going well."
