I don't deliberately carb up much. But make sure I eat a good supper and breakfast for long distance bike ride the next day.

The night before is to have a supper that's well balanced. Having nutritious pureed veggie soup the night before is a good thing for me plus other stuff. Breakfast which is eating stuff that digests easily, ie. waffles are great, scrambled eggs, etc. Besides I've reduced high carb in my diet long term for the past few years (very little rice now, only certain types of bread 1-2 small slices, certain types of pasta only, etc.).