Celtic manager Ronny Deila regarded his side's narrow win over Motherwell as comfortable but urged his players to be "more effective" in front of goal.
Anthony Stokes netted the visitors' winner at Fir Park early in the match after Celtic capitalised on a defensive mix-up.
But Deila's men missed several opportunities to add to their lead with striker John Guidetti among those not converting chances.
"The last 10 minutes because we didn't finish the game well, scoring goals, we got some troubles," said Norwegian Deila.
"First 20 minutes was top level. I want to show the players more of that. If we can get 90 minutes with that level, we're going to be a hard team to beat.
"We need to score more goals. It's about practice and skills and it's about getting confidence.
"I think John was very frustrated today but he has scored a lot of goals and strikers get these periods sometimes but he will come back.
"We win games, that's positive. We have a good mood in the group, it's a good atmosphere. We're working every day to improve and I see signs every day that we're getting somewhere but we are not there yet, it's a lot of work still."
Asked if he would change the team for Thursday's Europa League Group D encounter with Dinamo Zagreb in Croatia, Deila replied: "A little bit, but not too much."
Celtic and group winners Salzburg have already secured qualification to the next round.
Motherwell caretaker manager Kenny Black felt the Fir Park side had been "second-best" during the period where Celtic took a grip of the game in Lanarkshire.
"We showed them maybe a little bit too much respect," said Black.
"They're a good side. I don't think there was much belief in us in the first half-hour.
"We keep giving away silly goals and goals that we think can be prevented. It was a self-inflicted mistake from our point of view, which gave Celtic the lead.
"For the final 15 minutes of the first half and the whole of the second half Celtic created a number of chances through good defending from our point of view and good goalkeeping, we kept ourselves in the game.
"You never know what can happen towards the end of the game, we did say that. Even going down to 10 men, we showed a bit of character and for that I was delighted."
Simon Ramsden was dismissed for a tackle on James Forrest but the Steelmen then created their best chance with Lionel Ainsworth crossing for Lee Erwin, who headed wide.
"We were a bit unfortunate at the end with the header from Lee," added Black. "He came on and he could maybe have had himself a hat-trick. That's football.
"When we went down to 10 men, it was unfortunate. By all accounts, it was a straight red card and he deserved to go.
"The spirit and the determination from the players was there for everyone to see. We now come into a period before Christmas where we've got a couple of important games coming up so it's important for us.
"I certainly think there's the strength there to avoid relegation. I don't have any question about that. But the fact is we're in the relegation area just now.
"We've got a number of games coming up that are against teams who are in and around us in the league and it's up to us now to do our talking on the park."