I like to play in Elizabethan persona, and I wanted to be able to write letters as Katherine would have done. So I started looking for information on Elizabethan letter-writing.
I have gathered some useful phrases together, primarily from a book I found called:
A short discourse of the life of Seruingmen, plainly expressing the way that is best to be followed, and the meanes wherby they may lawfully challenge a name and title in that vocation and fellowship. With certaine letters verie necessarie for Seruingmen and other persons to peruse. With diuerse pretie inuentions in English verse. Hereunto is also annexed a treatise, concerning manners and behauiours." Imprinted at London for Ralphe Newberrie, dwelling in Fleetestrete, a little aboue the Conduit. 1578.
Quite a title. Anyway, it has a range of letters, from which I have extracted greetings, signoffs, and other useful phrases.
Right honourable, the consideration of my present calamaties, causeth mee to make my carefull complaintes with all humble and dutifull submission...
... Wherefore, I humbly yeld, and moste willingly submitt myselfe to your honours grace, favour, and mercie.
Right honourable. [and then launches straight into the letter]
... And thus leaving your worthinesse in the handes of your counsell, I wishe you those felicities which your owne heart desireth.
... I moste humbly take my leave, beseeching God to leave you long life with happy dayes.
I have this long time forborne to write unto you (deare father) not in any negligent respect...
... I moste humbly take my leave, craving your fatherly favour & blessing.
Wife, I do not a litle marvel at your uncourteous dealing towards me...
... Wherefore, if you will further your quietnesse, leave of those slaunderous speeches, lest the worlde condemne you, & yeld you up to miserie and shame. [no signoff]
I received your letters, which when I had read, mee thought they were so dark and obscure unto mee, that scarce I understoode your style...
... Thus leaving at this time to trouble you any further, I yeld you up to your owne follie.
I received your letters, giving you a thousande thankes for your wise and courteous answers...
And thus I ceasse, &c.
In moste humble and dutifull manner sheweth unto your honour, that whereas it pleased your good Lordship to accept most courteously my former letters, I am the more imboldened at this time to write unto your Lordships grace and lawfull favour...
My verie good Lorde, I have an earnest suite to your honour...
... And thus craving your friendly answere herein, I moste humbly take my leave.
... And thus farewell, wishing to you as well as to my selfe.
Being fully persuaded by some of my friendes, that your choler is somewhat digested, I am by that meanes the more willing to write unto you these fewe lines...
Forasmuch as the shortnesse of time doeth somewhat hinder mee at this time, to doe my duetie, as well of commendations, as of heartie thankes...
The long absence, sithence my departure, can no lesse minister occasion to write, then my wil is apt and agreeable to accomplish the same: not using any varietie of wordes, but rather a friendly greeting, according to your worthinesse...
... Thus reposing my selfe wholy in your wonted friendship, I committ you to the Almightie.
Maistresse, I am once againe inforced to write, and not without just cause...
[... if the recipient does what he asks ...] In which doing you bind mee alwayes firme & faithfull to you and your progenie.
Right worshipfull...
[... if the recipient does what she asks ...] In which doing, you minister unto us both an acceptable pleasure, and give us occasion, according to our power, to requite your courtesie.
I received your letter the xi. of August, the sight whereof hath ministered unto mee no small comfort...
Friend D, for that I did not take my leave of you, I am verie sorrie, and ashamed: neverthelesse, time did so fall out...
... And thus fare you well.
Right welbeloved sister...
... But leaving you to the gratious guiding of the highest, I bid you farewell. Your loving brother, A. F.
You can also see some examples of handwritten letters in my examples of the Renaissance italic hand. Some example greetings and signoffs include:
Right honourable and my very good Lorde...
... acknoledgeinge my selfe most bounde to your Lordshippe for the moste parte of my chefe hapines, humbly cravinge your Lo: [Lordship's] blessinge I humbly take my leave praying for your Lo: longe life and muche hapines. Tidworth. Your Lo: humble and moste obedyente daughtere. Lucy St. Johne.
My intention to attend your Highnesse to morrow (God willing) cannot stay me from acknowledging by these few lines how infinitely I am bound to your Highnesse...
... And so in all humility I Cease. From London this 18 of October 1605. Your Highnesse most humble and dutifull Arabella Stuart.
The Lisle Letters are from a little earlier, during the reign of Henry VIII. Here are some salutations and signoffs from Muriel St Clare Byrne's edition of the letters, with modernised spelling:
Right worshipful Sir, in my most hearty manner I commend me unto you...
... You shall have my good will and service, glad if it might lie in me to do you pleasure, as our Lord God knoweth, who preserve and keep you, with long life, good health, and to attain your gentle heart's desire. At Calais, the vij'th day of October, by your ever assured Honor lissle
My lord Deputy, my good neighbour and entire friend, I recommend me to your good grace...
... At which point, my Lord Deputy, my good neighbour and entire friend, I conclude; praying our Creator to give you good life and long. From Boulogne, this xxvij day of October, Entirely your good neighbour and assured friend, Oudart du Bies.
My good lord...
... and thus heartily fare ye well, my good lord.
My singular good lady, in most humble manner I recommend me unto your good ladyship...
Our Lord send my good lord and you long life in much honour, written at London the iiid day of December, at your commandment, Thos. Elyot, Kt.
Cousin Wayte, I commend me unto you, and have received the letter you sent to my wife, and well perceive the contents of everything therein...
... Trusting to see you this summer... Hol.
... And thus Jesu preserve your good lordship and my good lady.
... You be in my memento, and ever shall be, as knoweth God, who ever preserve you to his mercy.
... Other news I have not at this present to advertise you of, as knoweth God, which preserve you and send you as well so fare as I would myself.
... I desire you to have me heartily commended to my good lady your wife, and also Sir John Russell hath him heartily commended unto you. Thus the Holy Trinity preserve you and yours. From Grafton the first day of October, Yours assuryd to my power, ffranssys Bryan.
After my right hearty recommendations, these shall be advertising you that this sviij day I received your letterof the last of October which was opened ere it came unto my hands...
... And thus I rest, as wiling to accomplish your desire as any man this day living.
... And thus after my right hearty recommendations made unto my good Lady your bedfellow I will bid your Lordship as right heartily to fare well as I would do myself. At Southampton, the iiijth day of October.
Sir, in the humblest manner I can commend me unto you, and have received your letter dated the iiijth day of this month, and well perceive the contents thereof, which is no little grief to my heart...
... and thus I pray God send you as well to fare as I would myself, with much honour and long life. Written with the hand of him that had never a heavier heart. At your commandment, the vijth day of November.
... Beseeching you I may know your pleasure at your most convenient leisure, as you promised me at your last being here.
... From London, this Sunday, the xxixth day of November mvcxxxiiij, By him who is entirely your humble and obedient servant...