Any advice for helping an adult learn to ride a bicycle?

I have a dear friend who has never ridden a bicycle before. He is in his forties, and I have recently helped him purchase a bike and have offered to help him learn. He can drive a car, so I guess there will be analogies there that may help (eg look further ahead to avoid wobbly steering).

Do you have any tips, be they in general or specifically for helping an adult? Many thanks in advance.