Rank promotion in Aikido
Rank promotion in Aikido, as in any martial art, is a solemn and special occasion and there is an etiquette to receiving a promotion certificate. It’s important to realize that your Sensei is recognizing your hard work and effort with a promotion and at the same time, give them thanks for all of the time and effort they have put into training you. In addition, all Aikido rank promotions basically come from Doshu himself; so you are paying respect to him as well.
This video shows Osawa Sensei getting his 8th Dan from Doshu and is the perfect of example of how to receive a promotion.
When Sensei calls your name, walk up in shikko a few steps from Sensei and perform a kneeling bow. After the bow, move a few more steps forward towards Sensei, close enough to receive the certificate. Sensei will then read your certificate and present it to you. Accept the certificate with both hands, bowing your head. Keeping the certificate held up, walk backwards a few steps, then place the certificate to your left side and perform a kneeling bow. After the bow, return to the line.
If your knees make it unable to move in shikko, it is acceptable to walk normally, with all of the bowing etiquette described above. If possible, one should at least take a knee (left knee) in front of Sensei to perform the bows and receive the certificate.
Finally, while sitting in line in seiza at the dojo, it is considered poor etiquette to cross your arms (this is something I personally have been working on). It is best to rest your hands on your thighs or folded in front in you lap.