Well, I don't really give a damn about how much electricity I'm using.
I choose my laundry temperature to get clothing clean and fresh, which does not happen at temperatures lower than those I choose.
A slower spin will leave clothes wetter so they'll take longer to dry and could go musty more easily. We don't have a tumble drier.
The central heating is set at the lowest temperature at which David will not grumble.
I've found the spin speed makes very little difference at all (your washing machine may vary); it's lost in the noise on my graph. Heating the water is what uses significant power.
If you're not tumble-drying and you're not running partial loads (all our stuff goes in the same 40C synthetics wash, apart from towels and bedding which get saved up for a full load of their own), there's really not much you can do apart from wash your clothes less frequently. My clothes-washing frequency varies primarily with how quickly they get dirty, which doesn't have much to do with energy consumption.
The other big electrical loads are the kettle (which is of the boil-what-you-need type so doesn't run for very long at a time) and the oven (which, like the washing machine, uses a fair amount of energy to do anything useful). Obviously proper
BRITONS cannot be expected to go without
TEA, so there's limited scope there. Most of our cooking is done by gas hob or microwave anyway.
We do use a fan heater in winter, because we both have medical reasons for avoiding prolonged cold, and it seems more efficient to heat one room with electricity
[1] than the whole house and all the air passing through it with gas. We've just had double-glazing fitted, though, so I'm expecting a significant reduction in energy use there.
[1] Much of the energy dissipated by electronics contributes to space heating, anyway.