I got a wedge for the crib and after I got it my son started sleeping great in his crib. he has acid reflux so the wedge helped with that at night. it took him a week or so to get used to it but now he sleeps great in his crib. I also got a softer feeling mattress pad because a baby mattress is not comfy at all
I started out putting my daughter in her cribs for naps though out the day & then in her bassinet/my bed at night. & then I gradually started letting her sleep in the crib at night. She sleeps in her crib every night now & she's 7 weeks today. I think I started the process about 2 weeks ago, if that.