I am still using a single stage and mostly dip, weigh and trickle. Sometimes I would seat the primer, expand and drop powder using the Lee Auto-Drum. Both processes results in cases with powder sitting in a reloading block. Last step normally is to check the cases under the light to make sure they all have powder, and holding the block at an angle to compare powder height in each row. Normally this should be enough, but once in a while when I load say Bullseye in 38spl ot something easy to double charge, I would then intentionally load a double charge to to make sure I can differentiate between a single and double charge. I still think the final check is the gut. If it tells you that something is wrong, stop and evaluate if you need to proceed or not.