I would probably opt not to use lightweight interfacing just because starch is easier and has fewer problems. (I have seen interfacings shrink and bubble on occasion.)
For me, the easiest way to heavily starch yardage is to mix a 1:1 solution of Sta-Flo liquid laundry starch and water, "paint" this solution onto the yardage until the fabric is saturated, wait a couple of minutes to make sure the fibers have had time to absorb the starch, toss in the dryer, then iron with steam. My kitchen island provides a great area for doing this. To "paint" the starch solution on the fabric I use a large wall painting brush (costs about $3 at Walmart).
I would *never* use spray starch on yardage. Did this in the past, and it was very slow and time-consuming. It also does not provide the fabric with as much stability as the Sta-Flo method.