Multiball can score a lot of points if you know how to nail the ramps. I remember the Jackpot values were pretty huge. 5 million?

Jackpots increase to more than 5m by hitting the drops during MB (1m each?). Left ramp all day is pretty solid. It's just one of those safe return-able shots like Earthshaker where you just need to nail one shot over and over to cash in. Why bother with putting the ball into the pops 3 times for baseball when a ramp shot can get net you 3m? I usually go for MB just because it's more fun.

Hook has really simple rules, they're mostly laid out in the manual. No real hidden points for crazy scores I don't think.

I assume you watched the papa video, but if you haven't.

http://papa.org/2012/12/03/hook-gameplay/

I'm a minute into the video. Left ramp all day.

Ahhh. Haven't stopped by to play it yet. Might be for the best.

Have you tried right ramp all day? Right ramp twice starts a mode that lights the ramp (and VUK?) for 5m but I don't remember the specifics. The local Hook had very weak flippers so you couldn't really hit the left ramp beyond a very lucky shot, but the right ramp was much easier to make. I realize you want a more in depth strategy than ramp all day but we are talking Data East here.

Croc clock repeatedly is pretty solid, multiball becomes hard to lite, use both.

Make the skull shot to light the "Skull 20 Million" scoop shot. Make the scoop shot, then make the skull shot to score the 20M. I'm pretty sure that's the most points from a single shot (well, combination of shots).