This is a pro tip, but also a summer tip, take the ferry from Lower Manhattan to Rockaway and spent the day. The beach is great and the area is impossible to gasp that it's 30 min from Manhattan (without traffic) - Eat as many tacos you can, cause it's the best in the state of New York!
Nature is the only thing I sometimes feel that I miss in the city and though I love going to Central Park and Prospect Park it’s still a bit of a hike for everyday life. Thankfully there’s a ton of small gardens and parks all around the city and in the summer some of them turns in to secluded hideouts. My favorite is cramped in between 6th avenue, a playground and another street but it still feels like (almost) being in a little forest when sitting there.
Mcgolrick Park at midnight in the snow. Any early morning with all the bums and drunks passed out on Nassau Avenue. NYC still looks best between 3am and 6am, just before the light comes in to shine on all its flaws.
Chillhouse is awesome. It's a great place to chill out while waiting to meet a friend, read a book, or get your nails done. This all-in-one cafe has made it easy for the girl on the girl that needs some self-care time.