In terms of the members of the Society for Creative Anachronism, this process of  development allows a rich and unique opportunity to express a secret or inner self in a bold and dramatic statement, or in subtle and understated ways.  For the first time ever, one is allowed to design who he is going to be, and to create for himself a past and a future unfettered by the dictates of modern society.  This is part of the great attraction of the
Society.  We do not need to experience the pangs of our tender years or to be scarred by the follies of our awkward years... We spring forth as that person [persona] who we know ourselves to be inside.  Here we are not only allowed but encouraged to become someone new, some interesting being who existed at any time we care to choose between the fall of the
Roman Empire and the end of the sixteenth century.

My purpose is to directionalize your thinking toward the development or proto-development of a persona.

This will require you to make some choices.  Since the only one who will flourish or founder based upon those choices is the individual involved they are among some of the easiest choices anyone ever need make.  After all, it is just a game, and we are all just pretending.  Still, in order to formulate a persona with whom we can at all times be comfortable it is
necessary to direct our thinking.

First, and before anything else, my advice is to become a persona with whom you can live.  Anything you have to force will probably not be fun for you in the long run.  Think about how you wish to behave, dress, eat.   Consider about how much time energy and expense you wish to put into your persona.  Your persona may be a total break from your everyday
existence, or it may celebrate your own family history or ethnicity.  The alternatives are yours to choose.

If you are not certain about these things I recommend a path I call proto-development.  Proto-development consists of going to events in borrowed garb, talking to people about their personae and asking the hard questions.

Hard questions include:

Why did you choose the persona you have?

How much velvet did you buy for that outfit?  How much time did it take you to make it?

How much does velvet [brocade, etc.] cost per yard?

How do you clean it?

Do you clean it?

Can you dress yourself in that, and how long does it take?

Is it comfortable?

After proto-development is complete you need to look at other issues.

The clothes make the persona.  It is perfectly legitimate to base an entire persona on how you want to dress.

Basic truths should be self evident:

The heat intolerant should not choose a persona who wears lots of velvet and brocade.

Men who do not want to buy, make or wear hose should avoid developing a persona who would die rather than appear without hose.

Persons allergic to wool probably shouldn't be Scotsmen.

Chain mail bikinis are not only not period, but are uncomfortable and tend to get old rather quickly.

(Many inventive individuals have early personas for the summer, ones which live in peplos and chitons, and in winter go totally Tudor.)

If you like to wear sacks, choose an early persona.  You really don't want to run around saying you are an Italian noble woman from 1470 if you can't bear the garb.  The opposite also applies, an iron age celt will generally not be seen wearing a hoopland, or a boned bodice.

A few caveats apply:

Over the course of years I have been involved in changing room adventures.  One that comes to mind was that of a particularly shy woman who was struggling into a corset all by herself, and who rejected all offers of assistance.  She did not feel comfortable in a mass changing room, she did not feel comfortable hiking her bust up to the top of the corset, and she could absolutely not lace the thing herself.  Yet, obviously this was not borrowed garb!  High renaissance is clearly not intended for those who must dress unassisted.

Then there was the woman who was learning the galliard dressed in her gunna and kirtle (read: nightgown and robe).  The renaissance lord teaching her and she both had a surprise when he grabbed for her undergarment's rigid boning to assist him during a lift, and found out that women with such an early persona wear no such thing.

But all in all, driving ones persona off of the period of clothing one wishes to appear in makes good sense.
 

Another criteria for choosing a persona is decided by a particular affiliation which you have to a specific period of time.

If you embrace the Yorkists and spit on the Lancastrians (or vice versa) then chances are that you might like to develop a persona who lived during the War of the Roses.  If you have an affiliation for tales of Richard the Lionheart or of a particular crusade, then you can base your choice on that criteria.

While these choices may come about because you've read a ripping good historical fiction or seen Braveheart fifteen times, remember that you may not choose to be any character who exists in fiction or in history.

There is but one William Wallace.  You can be a distant cousin of his once removed, William of Whatever, or Stuart Wallace, or some such.

Which brings us to the subject of choosing a name.  The freedom of being able to choose your own name is wonderful and terrible.  Wonderful, because you know you'll like it.  Terrible because you have to not only narrow the field, but also have a name you will answer to and which will squeak by the rigors of the college of heralds.

The most important thing is to pick a name you love, one that won't wear out when you hear it or write it or correct the pronunciation of it for twenty or thirty years.  The second most important thing is that you be able to spell and pronounce the name yourself.  Anyone familiar with Welsh or Gaelic spellings will know what I mean.  Siobhan is pronounced "shivv' on."  Don't expect that everyone in the SCA will know that.  Don't even expect that most heralds will know that.

If your name doesn't go with your persona, well... make up a good yarn to explain why.

That brings us to another important facet of developing persona.  Are you in this for fun?  Are you in this for authenticity?  Or do you prefer a melding of the two?

I have met people of both schools and found them good company.  If you love role playing and Tolkein and Errol Flynn movies, there is a place for you in the Society.  If you hang on Barbara Tuchman, solid research and weave your own cloth, there is a place for you in the
Society.

You may start out with a fairly generic unresearched persona, and later on decide to totally go authentic.  You may spend years in the society wearing whatever you please as the mood hits you and never fix on a persona.  The most important thing is to enjoy yourself in the company of people who are expressing themselves as who they would have been, had they been given the choice.  After all, this is an idealized view representing the very best of a tumultuous and varied period of our history.