First rudder practice 'drill' needed here is theoretical. ie: A proper understanding of rudder's function. Here it is put basically and simply, but find a textbook explaining and illustrating effects of controls and read in full so that you first understand rudder's purpose and the need for its application as a part of the co-ordinated use of the primary flight controls.

Rudder => primary effect of this control is YAW about the NORMAL axis. Secondary effect is ROLL about the LONGITUDINAL axis. Putting it simply, although (especially in models) we can, we ordinarily don't and shouldn't use rudder as the primary control to turn the aircraft.

Once you understand that, it should become apparent using rudder to 'get a good line on landings' isn't either a desirable or efficient corrective technique. Correctively yawing the nose straight co-ordinated with the flare when using crab technique for crosswind landings excepted - only mentioned here for the sake of clarity.

Rudder's primary use is to co-ordinated application with aileron in turns to prevent a slipping or skidding turn. Just like the co-ordinated application of (up) elevator with a turn, the amount applied varies dependent upon the AoB which defines the rate of turn, the speed, and the size of the surface area of the control. It's something you just have to be aware of, and develop co-ordinated application throught repetitive practice.

A sound rudder practice drill for this is to perform simultaneous co-ordinated level turns reversing from one turn into the next performing a flat horizontal figure 8. First do them inwards then after a while, change to outwards. Perform these at a level and sufficiently close to you at moderate speed, but where you still have good effective control, so you can get a good visual appreciation of whether the turn is co-ordinated or not. Because we can't feel whether the turn is a balanced in an R/C model, we rely totally upon visual accuity to determine it. If you have difficulty determining whether the turn is balanced or not, ask someone who flies pattern to demonstrate unco-ordinated turns and then conversly turns co-ordinated with rudder to you so you can discern and appreciate the difference.

Now you have an appreciation, with constant repeticious practice, after a while co-ordinated use of rudder will become rote learnt and seem instinctive.