Story about Jerry Spence (WY trial lawyer in leather fringe jacket who represented Imelda Marcos). Patent appeal brief was 1 page, just a picture. He won. Sometimes you can persuade without writing-- don't be afraid of illustration.
Motions generally ask the court to do something, but you can also use them to educate the court/obtain an advantage/preview some legal or factual issues/prejudice the jury venire (because the media might pick up on it).
You do motions to dismiss, etc., before arraignment. Motions to supress are after.
99% of all questions are answered in the statutes (Chapter 5). Then there are local rules (Dane County, e.g.). The statutes also say what has to go into the motion, as well. See, e.g., § 971.30 (always say whether evidentiary hearing is required).
Parts:
Anything unfair, outrageous, or damning can be the subject of a motion. See also § 971.31(2)-(13) for an enumeration of legal issues.
Think about audience: judge (and which judge), prosecutor, or media and potential jurors. Think also about how you name your client (Mr., 1st name, etc.). Also consider how much info your motion is leaking: do you want to show the complete theory?
Note that you don't get an evidentiary hearing by default, you must make more than conclusory allegations (there's no summary judgment in criminal cases). The standard is US v. Toro 359 F.3d 879 (7th Cir. 2004): a prima facie showing.
Consider whether the defendant would need to testify, and also what the downside of losing would be: do we need to think about sentencing at this point, and are you foreclosing issues in federal court, etc. Also: do you have sading to raise the issue? do you need experts?
Make sure you have a summary of your issue and relief on the first page. Our motions will be 3-7 pages.
Consider the judge's eyesight: 13pt in body, 11pt in footnotes. 1" margins on all sides. We want something that lends itself to reading and quick digestion. Also, this complies with what you'll need on appeal, if it goes there. Book Antiqua font (not Times New Roman: this is optimized for newspaper, not full page work). Use a font that's called "Book" in some way.
Signature block is defined in § 971.30.
Also, there will be a brief, affiavit(s), and relevant documents. If you've got decisions from other jurisdictions, attach them (they may not be in the court's Westlaw plan, and they may not have the reporter at hand).
"Engage the reader in a single aesthetic moment."
Don't leave weaknesses out there for the opposing party to use against you: address them up front.
Make sure it's clear what you are seeking: by all means make sure that the thing you ask for at the end is what you said up front.