Reading the responses I'm pretty happy that I'm already doing most of the right things. Until I lost my rucksack last week I had a pretty good selection of tools/spares that were always with me on rides. I'm temporarily using a small saddle bag to carry stuff but I'm looking for a new rucksack as I feel they're more versatile and, as I ride straight bars, they're no bother at all.
There comes a time though where you realise you can't cover every eventuality, and just have to go for it.