Dylan Hartley and George Ford say England still have plenty of room for improvement despite their 58-15 win over Fiji on Saturday.
England made it 12 wins in a row and kept their unbeaten record under Eddie Jones with a nine-try victory at Twickenham, adding to their 37-21 triumph over South Africa in their autumn opener last weekend.
However, Fiji scored three tries of their own and both Ford and skipper Hartley believe there is plenty for England to work on ahead of next week's clash with Argentina, live on Sky Sports 2.
"I thought there was some good stuff, attack-wise," Ford said. "There is always stuff to work on. I thought it was a bit loose at the breakdown first-half. We tidied that up a little in the second half and played some good stuff at the end.
"We put an emphasis on the first 20 minutes to get a good start, we let ourselves down a little bit there last week so we are happy to make improvements in that area but fair play to Fiji, to be honest, it was a tough game and it took some doing.
"I thought it was a little bit off defensively. A little bit of urgency in the first half and not where we needed to be anyway, especially for the next two games and Argentina this week so we'll be hard on ourselves there and look to get better."
Hartley said he was happier with the opening exchanges against Fiji but insists England need to work on maintaining their intensity.
"I think there is plenty to work on, definitely. It can always be better," he said. "I think we started the game very well but probably dropped off intensity-wise. That's something we need to sort out.
"They are an attacking threat, they are amazing rugby players. The threat with them is they are big, physical guys who can move the ball pretty sharpish, they have got good feet and they offload out of every tackle, so we've got plenty to work on but we've got to respect the threat they posed."