Forest, who lost in the play-off semi-finals to Blackpool last season, have not hit top gear so far this season, drawing a lot of games, but even so they now sit in the play-off places following Saturday`s 2-0 win at promotion rivals Cardiff.
Earnshaw told the Nottingham Post: "If we want to be where we want to be, we have to have that confidence. We have to go on a good run. We need patches in the space of two or three months where we go unbeaten and where we also win games, picking up a lot of points.
"You can't worry if you lose one or two matches here and there. What matters is if you are picking up wins in the meantime. We want to be getting two or three wins in a row, then if we draw one, pick up another couple of wins after that."
On Forest`s away form that has seen them win just twice in nine Championship matches this season, he added: "We need that consistency, particularly away from home. To do this we need that little bit of luck, because we have played well away from home but we also need to force the issue a little more.
"We need to go to places with the intention to win 2-0 or 3-0 - and have the confidence to do that. We have almost got that mindset at home. It is not arrogance, it is confidence. We have to have that belief."