what I do
for taking to potlucks, etc. when it will have to keep for awhile, is to toss the pasta or grain, or potato with a little oil before dressing. Drain, place in an ice water bath to cool, drain again, then drizzle with a little oil, toss lightly to coat, then proceed with your recipe. The oil coats the starch and prevents it from sucking all the dressing up.
Refrigerating the pasta overnight also does wonders for keeping it from soaking up dressing (method of Szechwan Sesame Noodles). I coat the pasta with oil before refrigerating to prevent sticking together.