At that age, we just held our daughter or wore her in a wrap. I think she might have slept in the moses basket once for 20 minutes? From around 6 weeks, she would sometimes sleep in the swing as I needed to pump in the morning during her nap. Otherwise, she was held or worn and that worked well, and helped a lot with nighttime sleep. We started to put her down for sleep around 4 months and that was a smooth transition, but I didn't see any real reason to do it before then. I just made sure I had a drink and a snack and the tv remote within reach if she was tired. Swaddling is another option, and some people hold them til they are in a deep sleep and then lie them down (you can do the arm drop test, if you can pick up an arm and drop it, without waking them up, they're in a deep sleep). The thing with lying them down asleep is that the backwards falling motion triggers a natural startle instinct (it's supposed to protect them from falling off something). So if they aren't deeply asleep and even sometimes if they are, they'll startle as they go backwards. Sometimes lying down on a bed together and then shuffling over into a co-sleeping cot - so moving sideways rather than backwards into a sleeping space - works better.