My crazy Venusian terraforming idea is to attach mass drivers to millions of kuiper and oort cloud objects, and send them hurtling past Venus multiple times. The gravity drag would slowly but surely spin Venus up to a 24 hour day. Once that is achieved, the asteroids and comets would be used to create a moon for Venus, large enough to cause tides.
While that is happening, create a large shade between the Sun and Venus. This will freeze the planet's atmosphere onto the ground, allowing processing factories to gather up all the chemicals and start creating soil, water, rivers, oceans, etc etc. It would probably take a while for the vulcanism to die down, but the whole process would take millennia.
Like I said, utterly crazy and I'm sure wouldn't work for some flaw I'm not considering. I'd still like to try though!