Don't underestimate
this. Retreat to the baby's room so that he learns the connection that this room means time to rest. Sit with your baby with dim lights and soothe him for some time before placing him in his bed. No falling asleep in the living room or other rooms.
Your baby will sleep better in a cool room just like us adults. If you enjoy a warmer room for yourself, do not duplicate this in your baby's room. Humans rest better in cool temperatures. If need be, cover him with a blanket.
Always give your baby a bath even if only a sponge bath before bed. Just how you feel refreshed and soothed after a shower, so does your baby.
Be mindful of intruding lights. Do you have shutters where light peeks in? A night light is okay for your needs but nothing more as this interrupts sleep. This includes a bright clock.
A full belly is a happy belly. Do not put your baby to bed without being fed even if the routine is off. You will only wake up to a cranky baby very shortly after putting him down.
Experiment with aromatherapy. Lavender is said to soothe and relax our minds. Try just a touch of oil on a stuffed animal or on his clothing. (be mindful of allergies of course)
Massage your baby. Baby's feet get tired just like ours do. You'll be amazed at how soothing your baby feels with some light massage. Your baby will also soon make the connection that massage means time to wind down.
Routine is key. Try to keep up a routine. Plan around it as it is important to your baby's comfort.