<key>Identifier</key> should be in the format local.<recipeType>.<recipeName> (this is the default when using autopkg make-override
<key>NAME</key> should be the name of the app with spaces expressed as underscores.
<key>MUNKI_REPO_SUBDIR</key> should be set to <string>%NAME%</string> (except when grouping logical collections of apps e.g. Adobe Creative Cloud or MS Office installer and its updates in which case it should be <string>Name_Of_Collection</string>
<key>MUNKI_CATEGORY</key> - if it exists - should have its string value set to one of the categories listed here
For the <key>pkginfo</key> dict that autopkg passes to munki:
Change the string value of the <key>catalogs</key> to unstable. New applications should always go into the unstable Munki catalog at first. After they have been running for a while, this can be changed to stage directly to testing.
... <key>category</key> <string>Design and Media</string> ...
If it's missing, add a <key>description</key> and a string value describing the app (this will appear to users in the Orchard Software Centre)
If <key>display_name</key> is set to <string>%NAME%</string> and you changed the value of <key>NAME</key> above, you will doubtless want to change this to a more readable display name for users.
Scripts to be run by munki when installing/removing this app should be added to the pkginfo dict. Create a <key>preinstall_script</key> or <key>postinstall_script</key> and add the HTML escaped script inside the corresponding <string></string> tags.
The command $ sed 's/&(?!amp;)/\&/g; s/</\</g; s/>/\>/g;' <filename> is very useful for escaping scripts on the command line.