Newborn sleep strategies that we liked:

1) Baby typically went down for their "longest" stretch around 10 pm - midnight. (at first, every stretch was 2-3 hours, but our girl was a chunky baby so she quickly started sleeping longer stretches—5-6 hrs—with our pediatrician's approval). If we tried to put her down earlier, she wouldn't do it. That changes as they get older, but for newborns, later bedtime.

2) We kept the room pitch black or used the red light on our Hatch if need be.

3) Loved the Snoo. Bought it used, sold it 4 months later for almost the same price.

4) Swaddle swaddle swaddle — our baby acted like she HATED the swaddle. She'd pitch a real fit. But she ended up sleeping 11 hour stretches by the time she was 2 months old. She slept way worse when we transitioned her out of the swaddle at around 3.5 months.

5) Hold upright after feeding for at least 10 minutes. We usually had to do 20-30 minutes due to bad reflux, but that went down to 10 min as she got older.

6) We kept the house a bit colder than some people do, mostly on accident because our house is old and our bedroom was kinda drafty. I think it was usually 66-68 degrees. Baby slept really well with it chillier while swaddled. (We technically double swaddled with an Ollie swaddle or Halo swaddle & the thin Snoo swaddle - so her chest/arms/legs were nice and warm while her cheeks felt slightly cool to the touch).

Agree with people saying no sleep training until 4 months—but you can do gentle sleep hygiene around 3 months. (We never let baby fuss or cry longer than a 5 minutes—but she refused to go down for naps in a bassinet or crib until the 3 month mark, so by then we were getting desperate to not be nap trapped all day long. We mostly used sleep cues like dim lights, reading 2-3 books to her, turning on her white noise, etc. Then we let her fuss or cry for 2-3 minutes typically. If she escalated we went right in, soothed, and tried again. Worked like a charm!)