One idea: see which size & shape eggs you get the most of, and hatch those. They probably come from your best layers.
Another idea: pick a time of year when most hens stop laying but a few are still going. Hatch the eggs laid at that time.
	
		
	
	
		
		
			Hey everyone. I am looking for tips on how to breed for egg production. So far my attempts have been to simply hatch the largest best looking eggs I have.
I have 14 hens and I suspect 2 or 3 of them are not the best layers. Also many of them lay medium size eggs and I am looking for large or jumbo.
		
		
	 
Yes, if you want bigger eggs, it makes sense to hatch the bigger eggs.
But be aware of one thing: each hen will tend to lay bigger eggs as she gets older. So if you have hens of different ages, and you hatch the biggest eggs, you might just be hatching the eggs from older hens. That would not help choose hens that lay bigger eggs in their first year (but it might select for hens that still lay well when they are older, which is another trait you might like.)
	
		
	
	
		
		
			The issue is I have no idea what hens are poor layers or who is laying what eggs.
		
		
	 
Most eggs get laid in the morning, so if you are able to spend a few hours watching one day, you might get some answers.
If you really want to know, you can put one hen at a time in a cage, and see what egg she produces. This will at least give you an idea of what size and shape eggs are coming from who.
If you have a time when some hens are laying and some hens are not, you can check to see who is still laying:
https://www.backyardchickens.com/articles/who-is-laying-and-who-is-not-butt-check.73309/
Start by comparing a chicken you know is not laying (like the rooster) with one that most likely is laying (like the hen with the reddest big comb). If the differences are obvious, then you are ready to check the other hens and figure them out.
People sometimes recommend putting food coloring in the vent of a particular hen, to mark the egg when it is laid. When I have tried that, it sometimes worked and sometimes did not. Sometimes the hen would lay an egg without it getting marked (easy to tell if every hen lays, and no eggs are marked.) If the egg did get marked, the eggs might be marked for the next day or two as well. So it's something you could try if you want, but it may or may not actually work for you. Of course you can do several hens at once with different colors.