All of the italicized examples are from texts that I've written or adapted. Feel free to "steal" them but give me an "inspired by" credit if you do.
1. Use only the given names of the Kings and Queens, not their full SCA names.
2. Open with a greeting from the Crown.
[name] and [name], King and Queen of the East, to all good people of our land, greetings.
[name], King by right of arms, and [name], his Queen, to all to whom these present letters come, greetings.
3. Refer to the Crown’s authority to give awards, or to the Crown who created the award.
The King and Queen of the East are charged by ancient custom with recognizing those persons who perform great labors for the good of the Kingdom . . . .
Forasmuch as Our predecessors of blessed memory Viktor and Sedalia created and constituted the Order of the Sagittarius to honor and acknowledge excellence with arrow and bow . . .
4. Use multiple (usually three) verbs and nouns that mean more or less the same thing (buy a good literary Thesaurus!)
We hereby award, invest and endow [person] with the Order of the . . . .
and all rights, privileges and advantages . . .
forasmuch as our good and honorable [person] has proven himself to be diligent, doughty, vailaunt and laudable,
and we do further command, instruct and ordain that the said [person] shall henceforward bear the emblem of the Order upon his person in sign and token of the establishing of him therein
5. Is today a saint’s day for the recipient’s persona or culture? Check out the Online Calendar of Saints Days (http://medievalist.net/calendar/home.htm), which tells you the medieval saint’s feasts for each calendar day and the region in which that saint was honored.
For example, the entry for November 14 has (among many others) the following:
Modanus, bishop, confessor [GTZ: Scotland]
When writing a text for a Scottish persona, you would refer to November 14th as “the feast of Saint Modanus”
6. Avoid SCA-isms like “troll” or “feastocrat” or “autocrat” in favor of more general (and period!) terms like “gatekeeper” or “cook” or “steward.”
7. Refer to the fact that the award recipient is getting rights and privileges in addition to the award, such as the right to wear the badge of the Order upon his/her person.
8. Refer to the fact that we write things down to make sure they are remembered.
Because human memory is fallible, and knowledge of works done may be lost to time, good and notable deeds should, in a plenitude of wisdom, be committed to writing.
Lest the good and noble deeds of [person] be lost to the passage of time, we have caused these matters to be rendered in writing.
That the present award may be held firm by all our successors, we have had the present page drawn up and have fortified it with the authority of our ensigns manual upon 10 September in the fifty-first year of the Society.