In my experience the technique for sailing with the spinaker is different for singlehanded and 2 up.

One thing that remains the same though is that you steer the boat for max VMG then trim the sails accordingly.

In non hull flying conditions this is about 'feel' and the only way to get this is with experience

For hull flying conditions it is a bit easier,

For single handed, sit on the windard hull set the traveller in the middle, then set the main so that the top leeward tell tail is flying most of the time (80% will do)then cleat it and forget it it, a bit of experience will tell you where to put it, but don't fiddle with it just sail the boat with the rudder and spinaker.

Then steer and play the kite to keep the hull up. Keep the steering small as the rudders act like brakes, let the hull fly up and down quite a lot so that you can avoid big rudder movement.

Since the steering is the most important (you cannot loose the tiller) and you must hold the spinaker sheet in your other hand you can do no more.

For double handing it's much easier, position the crew between the lower hull and trapezing, moving them up as the wind increses, 2 extra hands means the helm can play the main as well as steer, just use one armfull of sheet to smooth out the steering, (steering is slow so try to do the minimum) the crew can also smooth out the gusts by moving a small amount in response to gusts and lulls, every so often look up and check that the leeward top tell tails are still streaming, it's better to be under sheeted than over sheeted.

Remember though the speed comes from the steering in all conditions KEEP THE RUDDERS AS STILL AS YOU CAN!!