Top tube cable routing – flat barred road bike – pics please

Still haven’t finished building up an Uncle John. It was going to have drops but due to some back trouble I’ve stuck on some flat bars.

I can’t see how to route the cables (rear brake and rear gears – front goes down down-tube) on the top tube nicely. Shifters/levers seem too close to head tube to keep cables on same side. Going round opposite side would seem to force a sharp turn to get to the respective cable stop.

Any pics?
Has anyone ever crossed a brake and gear cable?