I was wondering what the easiest way to figure out a LED's forward voltage is, using measurement tools. I know we can assume red LEDs to be around 1.8V - 2.2V, and that we have similar information for other LED colors, but I was wondering if there's a way to figure out without assuming that.

I purchased several LEDs that don't have a data-sheet with their specifications - so as an exercise I would like to write that information down. (I'm learning)

Most answers I see start by connecting the LED in series to a resistor, but I want to make sure the resistor is right before connecting it.