Pumping Moms! How much milk???

How much extra milk have you been able to get in a day? I've tried nursing and then pumping 30 min to an hour later. My best is in the morning of course I can get about 1 to 1 1/2 oz then next to nothing on my attempts after. I let him nurse whenever he wants and usually no longer than 2 hours between feeings. Anything else you find works?