To create a follower off the vanilla system, you'd want a quest to manage the follower, similar to DialogueFollower. The magic happens in the aliases. Take a look at how the vanilla DialogueFollower works, including the alias, and package stack in the alias. If you want to go off-vanilla, you need to do the same thing, but DO NOT use the same vanilla resources for ANYTHING. Those vanilla resources (quest, scripts, messages, factions, etc) can be modified by other mods, and this may not be desirable if you're moving off vanilla.

First, recruitment. It's much better with a custom voiced follower to have their recruitment dialogue in your own dialogue quest, instead of changing the DialogueFavorGeneric quest. EVERY custom voiced (vanilla) follower tries to change the same parts of DFG, and they all conflict.

For basic functionality you'd need:

• Alias for follower, with simple script (copied from DialogueFollower's alias script, personalized for yours)
• Copy of player follower packages used in DialogueFollower alias (note: need to edit package to voice goodbye line to point at your quest instead of DF)
• Copy of override packages in your own formlist for overrides
• Copy of DialogueFollowerScript as main quest script, removing reference to factions, unless you change factions to personalized factions (optional)
• Dialogue options mirroring DialogueFollower's player dialogue for wait, dismiss, trade, etc.
• Dialogue options mirroring DialogueFollower's favor dialogue, see favor tab of DF.
• Don't use PotentialFollower/CurrentFollower factions. (May need/want your own factions in place of these)