Did you know that the big center hole is not where the essential oil comes out of? That’s the air flow hole. The essential oil comes out of a pin hole along the inner rim of the orifice reducer.
It's super tiny for thin oils like Peppermint and bigger for thick oils like Valarian.
If you turn the wee oil hole to 6 o’clock, the oil will come out faster (great for thick oils). Turn it to noon, and the oil will come out more slowly. You don't even need to look for the hole, just slowly turn the bottle of you're having trouble getting the oil out.
Angle your bottle at 45 degrees. If you hold it straight down, you’ll block the air hole and restrict the flow.
Warming the bottle of some of the thicker oils (like Vetiver or Myrrh) in your hands, pocket, or armpit makes them come out easier. Or put a dropper top on them. You can get dropper tops from Amazon.