Some moms like taking the baby a bath, holding them, feeding them and putting them to sleep on their own. Others like myself like brushing the teeth, drinking water, reading a few books, praying and leaving the children alone to sleep for a bit. Other moms will rock their baby until they sleep until the child is a toddler. Remember too whatever you do this will most likely be your staple for years to come. Are you ready to commit to holding your baby when you go back to work? When you are tired? Have a 2nd, 3rd baby?
How to set a routine:
1. Gauge your child's needs. Is he already calm and doesn't need to be decompressed or is he a more energetic child that needs to be wound down before bed? If you have more than one child remember to be flexible to each of their needs. Until my daughter turned 1 she had to be held to go to sleep for a few minutes to sleep. If she wasn't held she would cry for 20 minutes or more. Now she will sit up talk to herself for a bit and go to sleep after 5 minutes.
2. Make time for your child's disruptions: Sometimes your child will need to pee after you asked him/her to go, or you changed their diaper. They'll ask for water, they'll want to talk or ask questions that suddenly just need to be addressed. Be patient and make time for these delay tactics. Your child is not doing it on purpose. They subconsciously are testing the parent/child boundaries, they are growing and they are learning. I tell my eldest, respect the bed/nap time.
3. Have help: If you have children with different needs ask your spouse/live in parent to take one child and you take the other and meet in the middle.
4. Occasionally skip a day: We all need a vacation, this is a routine not a sentence. Alternate with your spouse. If you work, have school have someone help you out.
If you started late with your child don't think you will never have a routine. No, stick it out and you will see after two weeks of doing the same thing your child will fall in line with the habit.