If you are rolling right doing an outside rolling circle you lead with left rudder.... if the plane is parallel to you and you begin you get on the left rudder to start the circle and then apply the roll.. by the time you get to KE you should have enough rudder to hold KE but not climb. If you continue this pattern the nose will not drop.

Dpending on how tight you want your rolling circle you can really get on the rudder when the plane is upright or inverted to keep the circle tight.

When someone starts to practice rolling circles I suggest they setup their low rate ailerion so they can peg the stick and have a nice slow roll. This way you can concentrate on the other sticks.