Rewiring trailer brakes, best place to ground them?

I would think one ground per axle would be best, if you lose ground on one side but not the other you could have really weird turning behavior. With my trailer it's light enough that the truck can easily stop it even without the trailer brakes (before I started a written checklist I twice forgot to hook up the cable to the truck so I know it works fine even if it's not as safe) so I'd much rather lose the brakes altogether than have it pulling to one side.