China to New york at 7/30 or 7/31 or 8/1. Economic class only. Any China departure city. Any New York airport. Any program.
The timing you're looking at, late July into early August, is actually decent for transatlantic award availability, though China to New York is one of those routes where you need to move fast because premium cabin seats (even economy on the better carriers) disappear quickly. Since you're locked into economy, the good news is there's more availability and the value proposition for burning points on economy long-haul is honestly questionable anyway, so cash fares deserve a serious look alongside award options.
On the points side, Air China flies direct Beijing to JFK, and you can book those seats through United MileagePlus, which is a strong redemption for economy given the distance. Star Alliance partners like Singapore Airlines (KrisFlyer) and ANA (through their own program or as a transfer partner) also cover this routing and sometimes have better availability than the operating carrier's own program. Flying Blue, Air France-KLM's program, is worth checking too since they price dynamically now but flash sales to and from Asia pop up regularly, the knowledge base actually flags a Flying Blue promo right now with economy seats available for 18,750 miles each way. That's a genuinely strong rate for a transpacific-plus routing.
From Shanghai, you've got more options. China Eastern and United both operate direct Shanghai Pudong to Newark (EWR) flights, and Newark is arguably more convenient than JFK for Manhattan anyway. You can book the United-operated metal through MileagePlus or use Chase Ultimate Rewards points transferred to United for this. China Eastern's own program is clunky for foreigners but Delta SkyMiles occasionally prices these at reasonable rates through the SkyTeam partnership.
If you're flexible between Beijing, Shanghai, and Guangzhou as departure points, I'd run a broad search across United, Flying Blue, and ANA programs simultaneously. ANA miles are notoriously good value for long-haul economy and the program transfers from Amex, Chase, and Citi. The window you're looking at is peak summer so availability will be tighter than shoulder season, but economy class on these trunk routes tends to open up more than business because airlines protect fewer seats for premium at the top of inventory.