Down blankets / duvets (or weighted blankets) boost a deep sleep. Their weight will put on pressure which gives a safe and calming feeling. Lavender tea and oils and wood oil trees have a calming effect as well, whereby wood oil trees (e.g. fir) stimulates the immune system and helps to strengthen deep sleep.

Fun fact: the funghi in Stilton (cheese) shall be able to trigger strong dreaming. Some report lucid dreams.