A., I may get some criticism for this because it isn't the most PC of approaches but we realized when our daughter was about 2 onths old that she was napping really well in her swing but not sleeping well in her bassinette at night. So we started putting our daughter in the swing for the night! It was the BEST thing we ever did - she started sleeping from 8:30 PM until 7:00 AM every night. And she still does! It is a dream come true.
We keep her in her swaddle in there and make certain she feels snug and secure. And we use the white noise machine at its least disruptive setting (the most boring some would say but it is working)! The other thing we do is "top her off" with a feeding right before she goes down for the night - even if she'd just fed a half hour before. That way her little tummy isn't what wakes her. They do say that smaller babies have a harder time going any length without food (and I don't know how big your daughter is) but our baby is actually in the bottom 5% and now taking 8 ounces in every 3.5 to 4 hours during the day, so I know she's getting enough food...
We got the idea from the Happiest Baby book... we loved that book. A neighbor actually gave us the DVD and we started there because it was all we had time for! As for the swing, we started her at a high speed a little at first and a little at a time, every three or four days, we've slowed it down. We now, two months later have her at the very slowest speed and, after a few days just in the swing but without any rocking at all, we're planning on moving her to her crib.
I'm certain others have found ways that work for them and their babies but this worked for us. We aren't co-sleeping people - we are newlywed and we like the few hours we get together every night! And she still takes good naps during the day but we are all sleeping at night.
Remember YOU are the only one who knows what works for your family and your baby. Experiment until you find what works for you and yours - but I'd suggest giving each experiment a few days before you abandon it. Some babies seem to have a tougher time adjusting to change at all... Good luck, A.!