The 28-year-old, who joined Villa from Feyenoord last summer, was part of a rearguard that conceded 69 goals last season.
With that statistic in mind, the Dutch international has acknowledged that he has to improve in time for the new campaign.
"I'm 28 and it wasn't an easy season. It was my first season in the Premier League and at Aston Villa, but I could do better I think," the Birmingham Mail quotes him as saying. "I expect more from myself. When we have a new season, I think it's going to be better.
"I'm never completely satisfied with the way I play, I always look for things to improve. I want to be better in personal battles, I want to win more headers, I want to make less mistakes.
"I just need to be better. I think with practice you can do a lot. You train like you play so it's 100 per cent every day."
Vlaar missed part of the last campaign with a calf injury, but he has now fully recovered from that problem.