The core safe sleep guidance, consistent across health bodies, is: always place baby on their back to sleep, on a firm flat mattress, with nothing loose in the cot — no pillows, no loose blankets, no bumpers, no soft toys — in a room that’s neither too hot nor too cold.
Room-sharing (baby’s own sleep space in your room) for at least the first six months is widely recommended, as it’s associated with a reduced risk compared with a baby sleeping in a separate room from the start.
A sleep bag or well-fitted swaddle (for babies not yet rolling) is generally safer than loose blankets, since it can’t ride up over the face during the night the way a blanket can.