Assuming a rim brake, the forces are applied in both directions, accelerating and decelerating, so I'd normally build the wheel to trail from the inside of the flange on one side, and the outside on the other.
On a disc-brake front wheel, acceleration turns the rim ahead of the hub but braking pulls the hub back, so I'd run trailing spokes to the outside of both flanges.
That's for rear wheels.
Assuming a rim brake, the forces are applied in both directions, accelerating and decelerating, so I'd normally build the wheel to trail from the inside of the flange on one side, and the outside on the other.
On a disc-brake front wheel, acceleration turns the rim ahead of the hub but braking pulls the hub back, so I'd run trailing spokes to the outside of both flanges.