The Netherlands' 2-1 Nations League victory over Serbia on Sunday took them top of Group A2 and gave them a strong chance of advancing to the quarter-finals in March.
“We fought like a family. We really had to suffer,” Xavi said.
“We had to defend, but we actually wanted to play possession football. But we couldn’t do that, and we couldn’t get a grip on the game because of Serbia, who did that really well.
“But when we switched to a different formation, things got better,” the Spanish World Cup winner added.
Xavi had the Netherlands play in different formations through his first four games, which started with a home draw against Germany, followed by an away win over Serbia and a come-from-behind 2-2 draw in Greece last Thursday.
“We now know how to dominate games in different ways. But we also know how to defend at times in a low block or a mid-block," he said.
“In terms of our core values, I’m very satisfied. The players are wonderful people. But in footballing terms, we need to improve in all sorts of areas.”
The Netherlands conceded a goal for a 12th consecutive match on Sunday and Xavi said they were working on becoming harder to score against.
“The most important thing is that we score one more than the opponent, but we want a clean sheet. That takes time," he added.
“I’m going to get some rest now first, because it was intense.
“I’ll continue to keep an eye on everyone. We are creating a family.”
The Dutch next face Greece in Amsterdam on November 13 before a trip to Berlin to take on Germany three days later.