You cannot be perfect all of the time, nor can you be at home for all naps, all of the time.
Generally, I try to follow an 80/20 rule. Keep in mind, babies under 4 months are a lot more flexible with sleeping on the go. Compared to a baby that is over 4 months.
If you are out and about at naptime with your newborn or baby under 4 months, I recommend swaddling them or using their sleeping bag in the pram or having them in the carrier for a nap.
Be aware when you get home, they may be more overstimulated due to the “nap on the go”, so it is essential that for their next nap, you allow a little bit longer to wind them down to help them soothe and send strong signals that it is nap time[LB1] .
With babies over 4 months, I generally find they will not do anything more than a cat nap while they are out and about. I would suggest trying to do this less frequently; the 80/20 rule comes into play again, 80% at home and 20% on the go.
If they have only had a short catnap in their pram, car, etc, they will need to go to bed sooner for their next nap. Ensure you prioritise the awake window (the amount of time that they should be able to stay awake for their age) and making sure that they have a full tummy before going down for their next nap, but not feeding them to sleep or feeding them just before the nap.
Say you went out for one nap one day, make sure you are at home for that same nap the next day. Anything more than 3 days, and you will usually see a habit-forming.
If I am starting with a client that has a baby over 4 months, my recommendation is that they commit to 3 weeks of being as consistent as they can to help their baby learn their new routine—missing out on a maximum of 1 or 2 naps a week while out and about during this period.
I feel it is important to note that getting out and having a walk in the fresh air or having short trips outside of sleep times is important for mums mental health and baby hormones, and circadian rhythm.
Take each day as it comes, know that babies are not robots, and no one is perfect, neither should your routine be. A routine’s focus is not a strict schedule but more, the repetition of something familiar, creating a habit and comfort around sleep and nap times.