It's entirely up to you if you want to follow a routine or not. Are you trying to put him down for a nap as soon as you see the tired signs. Since Nina turned 5 months she's dropped a nap during the day and is only having 2 naps a day now. I've tried following routines but unfortunately her naps are at different times of the day, depending on what time she wakes in the morning and how she slept the night before.
The only 'routine' I do like to do is when she's awake, I do the 'play/feed/play' routine, then put her to bed for a nap. The more I play with her, the more tired she gets and will gnerally sleep 1.5-2.5 hours at a time now.