From the original post on this thread:

...a nice, concise list of the rules for double dactyls...

(1) The entire poem is a single sentence.
(2) There are two stanzas of four lines each.
(3) All lines except lines four and eight are two dactylic metrical feet in length.
(4) The first line is usually a rhyming nonsense phrase. For example, "Higgledy piggledy."
(5) The second line often, but not always, introduces the topic of the poem. If you are writing about a person, it helps if the name of the person you are writing about is naturally in the form of a double dactyl. For example, "Hans Christian Andersen."
(6) One line within the second stanza (often the sixth line) is a six-syllable, double-dactylic word, usually an adverb or adjective. For example, "Parthenogenesis."
(7) The fourth and eighth lines are not double dactyls. Instead, these lines consist of one dactyl plus a stressed syllable.
(8) The fourth and eighth lines rhyme with one another. Given the special form of the fourth and eight lines as mentioned in the preceding rule, it follows that the final, rhyming syllable of these lines must be a stressed syllable.

Stanzas two; four lines each;
Start off with nonsense; all
Lines except Four and Eight:
Two-dactyl mix

Sixth line is often one
doubledactylic word
Rhyme Four and Eight, skip their
Counts five and six.

It's imperfect, and incomplete. Can we refine and improve ?