Most of my aiki-dohs seem to be some form of accidental self-injury..
Doh#1: with the 1st bokken kata, swinging the bokken round and hitting myself in the kneecap...
Doh #2: in the 1st jo kata, embedding the end of the jo straight in my thigh when it was supposed to go past me
Doh#3: 2nd jo kata: the end of the jo got caught in my sleeve, it took me ages to free the jo and continue the kata. all this in front of the class
Doh#4: when I was doing some tantotori technique, can't remember which one, I threw my partner and also accidentally the tanto with it, it hit her in the head when she was rolling