How to properly export a package into ready to upload .unitypackage

[Myong]

Does anyone have a tutorial i could reference off of for proper setup/exporting of a full avatar package?

Because to how many models ive messed with i have a rough idea on how you shouldnt:
-add required scripts to the package to prevent errors (generally due to multiple being in the package or to prevent using outdated versions)
-name the folders nicely for easier editing/setup

The few times ive tried fully exporting an avatar the pre-setup .prefab generally breaks and the scenes stay empty in some cases rather then what i saved it as.

[solamistaken]

I personally use Beretta's Avatar Packaging Tool (part of this tool set) and then package the folder it creates