mrje1
I am not intimately familiar with the AIGA agreement, though I do frequently lead online sessions about reading and writing contracts for independent professionals. So my experience with contract templates for a variety of practices serves as the basis of my response.
I assume by AIGA Standard Agreement, you mean the one found here:
http://www.aiga.org/standard-agreement/.
I thought the accompanying information did a pretty good job of explaining their approach which is, basically, this is what you need in a contract, format it in a way that makes you comfortable.
If you're submitting a proposal to a client and you expect them to sign off on the proposal without a separate LOA or contract, then there is some logic to making your proposal (what you'll do) as the focus of your presentation with the terms and conditions, pluse any appendices (Schedules or Exhibits) as what are known in hard copy versions as "attachments."
So, you might write your proposal and place the signature lines at the end of that part. If you do this, make sure the body of your proposal refers to the existence of the terms and conditions and any other attachments. Best would be to have a place for the client to initial anything that come "after" the signature--in fact, if you offer any choice in the proposal, you should include a place for both your initials
there, too. You want to do this so that your client can't t later argue that s/he didn't see the information and they are therefore invalid.
You should give the client an opportunity to modify the agreement, because it should be the agreement you both believe you can abide by. A good client will discuss with you any changes s/he might want
before they sign, but sometimes this just doesn't happen. This is why you should not send a signed proposal to a client: have them sign first and then return the document to you. You review to make sure that nothing has been changed and all the required signatures and initials are there, then sign/initial yourself and return a copy to the client.
Alternately, and many lawyers will do this, you could write a letter of agreement that focuses on the terms and conditions, and attach the proposal to it.
Or, and this is what I tend to do, write a letter of agreement that includes both scope (what you'll do) and terms under which you and your client agree to be associated.
Now, for numbering. If you generate a lot of files and emails in your projects, and especially if many of them have the same name (Proposal, letter of agreement, interim report, invoice, invoice reminder, etc). You may find it useful to devise a shorthand system that will keep work organized and help you quickly figure out what you need to know or do. You might then want to include the identifier on your correspondence, so that the client can refer to the same number.
The most important thing about a numbering system is that
you find it logical and easy to use. What works best will be a balance of the accounting systems you use, plus the frequency of client-work. I know some people who number sequentially within every calendar or fiscal year, based on proposal. So, the first call you get in 2012 is numbered 2012-001, the second 2012-002 etc. You might then add to this an indication of what the document might be e.g., 2012-001.pr might be that proposal, 2012-001.loa might be the letter of agreement for that project, if you have one 2012-001.ir1 be the first interim report, and so forth.
Because I have clients who pop in and out of my life over years--decades even--I use a system of
[CENTER]AAA-12-01.typ/CENTER]
that is 3 letters that indicate the client, two digits for year, and the sequence within the year. This makes it possible for me to quickly identify everything I've done for Acme Art Advisors to see how I presented work in 1997, whether they paid promptly or I had to invoke a service charge, and more.
I can then also integrate this with my notes about client referrals etc.
<sigh> there's more, of course but this is already TMI, I think.