How do you make repetitive training interesting? I am very much of the view that you can only 'learn' a technique from repeatedly doing the same technique.
first..IMO an instructor can only do 50% of the making a subject interesting..the student has to do the other 50% themself.
As far as a suggestion goes, see if you can focus on fine tuning each time you do the action. As an example let's take learning to ice skate. Every time you put on the skates you are technicaly doing repetitive training. The first several times you are just learning to keep your balance...then you are learning to move. At that point you have the real basics down. After that, every time you get on the ice you work, maybe without realizing it, at getting better, smoother, more fluid, maybe you try 'tricks' which really ammount to nothing more than better and better control of moving on the ice. You fine tune.
You can do the same thing with any physical or mental activity you are training yourself to do, Aikido included. Problem is...you have to be interested in doing this. If you aren't (or your student isn't) intersted in this no ammount of harping on it from any instructor is going to be effective.