Mathias:
Asking "how" and "how much" to lube a minie on a board like this is a lot like tossing down a couple of pucks at a convention of trying-to-reform hockey players - sure to start some action!
The short, unsatisfactory answer is, "Whatever works for you and your rifle." The next longer is, "There are at least a dozen ways to lube 'em in just about any configuration you can imagine, and somebody out here will swear by each and every method."
I use a nifty little plunger-pump device in a little tin can, designed by a sutler who caters to the skirmish trade, that you heat up on the stove. It squirts just a bit of melted lube up into the base while the rings are getting a quick bath. It is the last step in my ammo assembling operation, so each minie is already sized and set over powder in a cap-plug-like vinyl case. Each goes to the muzzle with a tad extra exterior lube that shaves off upon loading. Better a little extra than not quite enough.
Some really good shooters I know lube just the grooves. Others use a dab of white lithium grease in the base. One uses the same food-grade lube I use, but cold-fills the base flush with a little screwdriver-cum-puttyknife. Yet others use the cookie-sheet mass melt technique.
In sum, it's pretty much whatever floats yer fouling and appeals to your sense of efficiency and/or functional practicality. Or makes for a more interesting argument! :thumbsup: