I haven't done DLH valet, I believe it's for all rooms (whereas Newport was compass club etc) so it's probably a bit easier. You literally drive up, as you get out they will bring a trolley and help you load onto it. You'll have a ticket for that then you hand over your keys and they park up the car. We then left the keys there (in Newport bay) as didn't need them and they then have them allocated to wherever they parked car. I didn't tip, don't think you tend to in France (though may be corrected).
For going back it was the reverse, our luggage was taken from our room downstairs, we advised of name when we got to car park and they then go pick up car and drive to the doors. help pass things over and you're done :-)