Jersey coach Harvey Biljon said his first game in charge of the struggling side had shown him that there was plenty of room for improvement.
Rotherham Titans swept to a 35-22 victory at St Peter, leaving Jersey four points off the bottom of the Championship table.
"Certain parts were very encouraging but others were very frustrating," he told BBC Jersey.
"We need to focus on ourselves and make sure we don't make the same mistakes."
Biljon joined from Cornish Pirates in early January, but initially took a back seat with forwards coach Steve Boden taking charge of Jersey's recent fixtures.
The former Wasps scrum-half said Jersey had made life difficult for themselves in tricky conditions at St Peter.
"Every time we got ourselves into the game, it was our own unforced error which allowed Rotherham back in," he said.
"Probably one of the most important things to come out of this game is that we need to learn to control the ball better, particularly at key times.
"There are things we need to improve between now and the end of the season and it's going be about the players' reaction during this week, and next week and every week until the end of the season.
"We probably didn't play the territory as well as we should have in the first half and probably didn't hold onto the ball as well as we should have in the second but overall there are lots of positives."