i wouldn't say there is a "best" but the easiest to use is foil tape.
it is not necessary to get the foil to go around the whole bait. in fact, it kind of messes up the foil job if you try to get it to go all the way around.
if you try to cover it all in foil, the foil will wrinkle because it can not conform to curves and contors of the bait. it would be like trying to wrap a piece of paper around a golf ball without getting any wrinkles in the paper....pretty impossible.
i try to get the foil to completley cover the face of the lure (flat sides) and then just cover a little bit of the back and belly (like you have done....maybe a little bit more though).
maybe you are trying to use contrasting colors to add some attracting qualities to the bait, but if not, you should really try to match the color of the back and belly a little better to the foil image. it will really make the bait look a whole lot nicer.
i hope i'm not coming off sounding rude or anything, because i'm not trying to say your baits are bad, im just giving you suggestions for improvement
but it sounds like these swim pretty good! the action is what catches fish, not the paint!
keep at it man!