We are only scratching the surface at the moment, but getting lots of great suggestions from this thread. Thank you.
We buy our washing powder in cardboard boxes, use our water bottles and reusable coffee cups when out and about, use cloth shopping bags and walk whenever possible, rather than take the car for short journeys.
We recycle our glass / metal jam and marmalade jars to store small amounts of leftovers in the fridge, make overnight oats and as containers for odds and ends or home made gifts (sewing kits, truffles, peppermint creams, mini manicure sets).
On the cereal front, Weetabix, Shredded Wheat and Porridge Oats don't have plastic inners.
I do feel we should only move to a non-plastic option when replacing stuff. No point in throwing anything away regardless, but wait until it is broken or no longer fit for purpose.