I found that thinking of it as a rhythm rather than a fixed routine made me less anxious when the little moving target that is my DS would throw me a curve ball! Growth spurts, teething, colds, the clocks changing...all these things will knock your routine!
I would agree that a bedtime routine is a good place to start - it may not evolve fully for a few months yet, and don't beat yourself up on things having to be at the exact same time every day, but certainly winding down, quietening the house, a bath, that sort of thing, also really helped us to feel like the day was coming to a close. Got us an hour of grown-up time, too!
DS is 8 months old, and he's still changing routine wise, naps get dropped, solids get introduced, but the bedtime routine is now solid gold and he is always sound asleep by 7pm. He doesn't always stay asleep, and still doesn't sleep through, but he will, one day...:)