Axial rolls are easiest, also the most boring.

Trying to perfect barrel rolls has kept me entertained for over 4 decades. You have to fly the model though them, there is no other way. Every airplane design needs slightly different inputs and timing. On airplanes that are more neutral with little cross coupling between the rudder and aileron inputs (a plane that can yaw without rolling), I find that right rudder while rolling left with a bit of up elevator works well.