Arrangement is the part during the rhetorical process when you decide in what order to put your arguments. Depending on how you write, this part might happen after you've written a draft, or you might do it in the form of an outline before you start writing paragraphs. Regardless of when you sort and organize, there are several principles to keep in mind.
start where your audience already is--begin at the beginning and don't stop until the end arrives.
make sure the introduction tells people what you are going to talk about, and why they should care. Then explain how you will proceed.
give the back story only if necessary (don't tell people things they already know or distract them with things they don't need to know)
answer questions in the order they are most likely to occur to your audience.
define things before you evaluate them.
name things before you explain them.
state the problem before the solution, and make sure the audience accepts that the problem is their problem before you offer to solve it.
signal transition from one thought to the next by indicating the relationship between them
avoid useless arguments--don't debate the impossible or the inevitable, and don't debate issues you haven't the power to affect, or before people whose powers lie elsewhere. (see stasis and asystasis)
conclude by reminding your audience what they need to do, why they need to do it, and if necessary motivate them to act (topics of urgency, scarcity, regret, etc.).
In general, a well structured sentence has subject, verb, object word order. A well constructed paragraph has every sentence in its place. A well structured document has every paragraph and every section in its place. If you're not certain about the arrangement in any given sentence, paragraph or document, scramble the order and see what happens. If it doesn't seem to make any difference, you don't yet know what you're talking about. Also, keep in mind that the arrangement that best suits your audience is almost never the order in which the ideas occurred to you. If possible, use a readily discernable, preferably visual, pattern: chronological, geographical, geometrical, logical, proportional, antithetical, whatever concept of order lends itself to the subject and the audience.
The classical tradition offers patterns or what we today might call boilerplate, a layout into which you pour your material. The typical pattern of arrangement handed down by rhetorical lore is the argument as it might be performed in a court case. Below is an example from Roman tradition, specifically an interpretation of what is offered in Cicero's On Invention, a textbook on rhetoric which he is said to have written while still a teenager (14, as I recall).
Introduction (exordium)
There are basically two kinds of introduction: the direct and the indirect. The indirect method (sometimes called insinuation) is used when the audience is likely to find the subject matter repulsive. In most circumstances, however, getting directly to the point is preferable to dancing around it.
Division (partitio)
State the issue (stasis) and the various opposing opinions
Give your position (what you agree to, where you disagree)
Present your argument in brief
Background (narratio)
Background Information
Who, what, where, when, and why. Only what is useful
Define key terms
Defend uncommon definitions and uses
Use technical terminology exactly as the experts do (but avoid technicalities with non-expert audiences)
Do not define widely understood terms
Confirmation (conformatio)
Present the arguments that support your position
Probabilities
Enthymemes
Examples
Maxims
Signs
Data
Refutation (refutatio)
Present the arguments that question your position; then refute them
Question the assumptions
Deny the premise(s)
Grant the premise(s), but deny the conclusion(s)
Question the examples
Provide counter examples
Invert the terms (refute laughter with seriousness, seriousness with laughter)
Recombine what is divided, divide what is whole
Conclusion (peroration)
Explain the benefits of your position using the topics of expedience,
honor, justice, practicality, and/or whatever else seems appropriate.