DISHWASHERS CONNECTED TO SINK WASTE. I clip a dishwasher waste hose so that its highest point is just below the work top. Its connection to the waste pipe is before the trap.
WASHING MACHINE WASTE HOSE. I clip the waste hose so that its highest point is a little lower than the top of the soap tray so that water can run to waste and not flow out of soap tray if a supply solenoid valve fails.
Manufacturers Installation instructions should be studied carefully.