I know I've written about this a couple of times in my earlier postings, but here is the almost definitive guide. I'll also be putting this on into a separate tab soon, so that beginners can just click that to refer to it anytime.
1. Fudo Genri/ Immovable principles:
4 points towards Body, Mind and Spirit unity...
a. Concentrate on seika tanden/dantien or center.
b. Mind, heart and body must relax.
c. Feel the Ki in any movement and extend it
d. Mu Shin (no mind, or stop thinking too much)
2. Kihon Genri/ Basic Principles:
These are movement principles that follow the Aiki Law or Natural Universe Law.
a. Chushin: Center line. Always move from your own center line. Connect to uke and bring him into your center line. Do not move his center line separate from yours.
b.Shuchu: Focus power starting from the mind into the body.
c. Kokyu: Breath power, connecting the energy of the body and the physical aspects.
d. Enshin: Circular movement or more precisely, spiralling. You can spiral inwards or outwards.
3. Aiki Genri:
Energy principles, essential in resolving conflict.
a. Awase: Blending, to harmonise with incoming force not to avoid or fight it. Body leads the mind.
b. Musubi: Connection, stage two of harmonising. Musubi can occur in many levels not just at the physical level. Mind leads the body.
c. Nagare: Fluid movement, there is no stop in movement or conflict. Joining with partners energy and moving synergistic-ally.
d. Takemusu Aiki: Unlimited manifestation of Aiki. This is a stage when you are living in harmony with the universe. Technique is not essential because your opponent cannot defeat you since he will be fighting himself.
5 Stages of Understanding Aiki
1. Aiki no Kokoro: Understand and belief within your heart the principles of Aiki.
2. Aiki no Genri: Know and understand the Aiki Principles.
3. Aiki no Waza: Embody the techniques of Aiki in training and life.
4. Aiki no Chikara: Resulting from training and embodiment of Aiki principles, achieve the power of Aiki.
5. Aiki no Seishin: True Aiki. Its 'switched on' without your active participation.