Is this your first child? Because it's not unusual for FTM to have this idea that babies are just put down and go to sleep, just like that, and dont realise just how much hard work, time and forethought goes into making that happen.
You need to give your baby a lot of help to be able to sleep independently. If you're assumption is along the lines of baby doesn't just quietly go to sleep when placed in the cot/crib, therefore my baby won't sleep independantly then really the only problem is your expectations. It's never easy, for any baby or any family.
Some things that make it easier for baby to sleep independantly:
- Sucking. Natures way to sooth and calm baby to sleep. The independant way to allow for sucking to sleep is the dummy.
- Movement. Gentle, consistent, even tempo swaying.
- Going to sleep where they stay asleep. So not being put down once asleep, but starting off in the place they stay.
- Swaddle. Recreates womb-like conditions and the sensory deprivation helps calm the startle reflex.
These together, the ideal for independant sleep is baby going to sleep in something that moves - pram for example. With a dummy and swaddled. Baby put in there awake and lulled to sleep with rhythmic, even back and forth movements (this ideal is therefore on-the-spot pushing, rather than being out for a walk when the movements are less even).
Another option is naps in the bouncy chair. Park yourself on the sofa with baby at your feet. Use your foot to bounce evenly and reinsert dummy as needed. Keep movement going for about 10 minutes after falling asleep then slow and stop. Restart at first signs of stirring awake, to try and resettle.
If you want cot naps then you need to work on getting aby to go from awake to asleep in there. You can't use movement because cots are static. So will need to add extra layers of support to help baby go to sleep. So try: Swaddle, dummy, white noise, and patting to sleep. The dummy is necessary otherwise baby will cry. Baby wants to be put down awake and ready for a nap, but not over tired and not almost asleep already.