Different boats require different variations of the techniques for light air.
Actually trying to get the windward hull out in very light stuff is mostly a waste. Note that I said very light. In most cases you will end up depressing the leeward hull significantly to achieve it, and the drag savings will be minimal. We've tried trapping to leeward to get the windward hull out, it's fun but useless from a speed standpoint.
Just about everything else I've sailed has benefited from crew on the lee bow and skipper at or on the crossbeam, near the mast if possible. In that position the skipper should run all the sails, as it is often very inconvenient for the crew to do the jib without moving around, and the skipper can actually see what the sials are doing. Mast rake can play a big part in how far the skipper and crew need to be forward to get the sterns free.
As for tacking and jibing - I've found that the attention needs to be placed on keeping the boat moving through the water, and crew weight placement can be more important here than sail handling. Worry about keeping the hulls moving through the water and getting the sails over second. Trying to do a roll tack in the really light stuff is mostly a waste. Consider having the crew cross the boat in front of the mast instead of behind can help.
For the most part, stay in the middle of the course and try to take the most direct line to the marks. Chasing breezes on the outside of the course often leaves you without wind outside the course with more distance to recover.
That all having been said - the Hobie-18 is a big time stern dragger, and mast rake only made it worse. In almost all conditions I found that a lot of mast rake made the boat an absolute dog downwind, even if the sterns weren't dragging. Even after I added the spin, in most conditions I ran the mast all the forward. If I raked the mast in anticipation of heavy air that did not materialize I unraked it on the water to keep from dying. Can't emphasize this enough with the 18.
It has been touched on, but I would reiterate that finding the wind and sailing the boat well are critical to going fast in the super light stuff. I very rarely change the way I rig my boat (Hobie 17). Possiby kick the windward rudder in the light stuff.
Having good wind indicators (VHS Tape) is very handy. I don't look at the tell tails on my sail too much, but I'll glance up at the top ones if the boat feels sluggish to see if the lee side is stalled. It's best to get a feel for the boat so you don't have to look at it (get your head out of the boat). I try to spend 2/3 of my time looking around for wind by watching the water and the speed and angle of other boats. When the wind is light, you can actually listen to the bow ripple and the flutter of the VCR tape to hear accelerations. Also, if you turn off the rachet on your main blocks you can more easily feel changes in pressure. I almost constantly adjust my mainsheet, one or two inches out in lulls and one or two inches in for puffs.
Just some suggestions.
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I would suggest looking at this a different way. Your foils, that is your boards and rudders, are your
underwater sails
. And just like you can benefit from more sail area in very light winds, I believe you can generally benefit from more foils at very low boatspeeds.
Hence, in very light air, I keep all of my foils down all the way around the course. As boat speed goes up I consider reducing my foils. So in medium to medium+ I might start pulling my boards part way up for downwind. In really heavy air I might pull my boards part way up and have them part way up all the way around the course.
The way I look at it you need more foil in light air to prevent stalling the foils (very high drag) and at low boat speed the surface drag from the foils operating with good flow is minimal. At greater boatspeeds the foils will not stall (so you need less of them) but the surface drag begins to increase significantly (so you pull them up) reducing surface area and surface drag.