The equaliser conceded against West Ham United yesterday was the first goal QPR have shipped in the last five games.
That is a marked improvement on the 16 goals they conceded in Harry Redknapp's first nine games in charge.
"We have realised now we have to be tight all over the park," Hill told the Fulham Chronicle. "We had been giving teams far too much time on the ball and we have tried to rectify that.
"It's been a terrible season for us, but we're trying to sort that out, and we're starting to click both as a team and a unit at the back.
"We have found something extra these last four or five weeks and we are now much harder to beat."
QPR remain bottom of the Premier League, five points from safety.