Buy an NFT that is undervalued off opensea utilising rarity, nfthud.io (if anyone in the group has access), social media metrics, artist reputation, etc. then sell at an auction house for a larger than usual profit, since people at auction houses have a shit ton more money and will definitely overpay like they did on BAYCs and Beeples.
I will let the community decide which NFT would be the best to flip but it most likely would have to be something between 2-25 ETH and looking to flip for at least $350,000 to $3,500,000, possibly more, things have sold for upto $70mil.