Is there some sort of standardized methodology for counting birds?

I currently have a fluttering mess of activity at my two hanging feeders + heated waterbath, and my attempts to count species reminds me of this question which I’ve been wondering about for a while.

Here is a fairly arbitrary guess at numbers right now:

15 white-throated sparrows

20-30 house finches

20-30 juncos

4 cardinals

3 blue jays

2 red bellied woodpeckers

2 house sparrows

2 starlings

2 robins

It is just a mass of flying in & out, back & forth. I’m confident of the single-digit counts, but anything over 10-12 (with all this movement) becomes guessing. So how do people count?

I’m a Quality Assurance professional by trade, so I’m trying to imagine some sort of sample size per unit of time, or per area of ground, but it is not like taking a sample of a raw material shipment nor is it like counting bacteria colonies on an agar plate, because they don’t move around nor take wing and fly away!

Is there an official counting method?

J Gary