You can experiment and find what works for you. What you are making can make a difference too. If you are working with precise measurements, pressing/starching will help. If you are working with triangles or other bias, starch helps. On occasion, I have sewn a piece or two without pressing the seams and not been happy with the results. It made a tuck by the seam. I prefer to press, and most of the time I starch too.
If you are looking to speeding up your process, chain piecing can help.