If we take a logical approach to this question, we have to look at how we take in information and how we interpret it.
We use the five senses to take in information to our brain, sight, smell, taste, touch, and hearing.
We can eliminate two of this senses smell and taste because we don't use them in learning Aikido.
So that leaves us with sight, touch and hearing.
Generally people favour one of these senses, but still are using all three to interpret the information.
Sight - Watch and learn, Touch -- Do and learn, hear -- Listen and learn.
The problem comes when interpreting the senses information.
You can get several people to watch a particular technique being executed, and you will get different interpretations of what went on.
Why is this? I believe that there are several reasons for this
1. Preference, People look to find there own preferences in the technique (judgemental).
2. Limited understanding
3. Some people are generally not observant.
So to teach people how to learn, we have to work on the senses, find there favoured sense and find what preferences that have when doing technique, (hard, strong, soft, flowing, sharp etc.) i.e. understand there interpretation of the technique and use this to guide them build there understanding, observation and maybe given them additional or other preferences that they can work on.
Measure your ability. This can be difficult you need a goal(s) (an ideal) that can be used to measure yourself against i.e. I want to be like my sensei or I want to be soft, flowing etc this gives motivation.
I believe people learn faster doing simple exercises to achieve there goals, created exercise that complement there preferred sense and preferences also try to build up there lesser senses.
Have a goal, find which sense you prefer, develop exercises around that preference and sense.
Be patient and have fun.