Treat him like you appreciate him, and do your best to spoil him in subtle ways to encourage him. You can also make him feel special by making him his favorite meal or giving him a nice foot rub to calm his nerves.  Another great thing to do is to help him put his things in order before he gets home. Your man may not always have the time to be organized, so it would be really helpful if he comes back to a more organized house. Note that these are ways you can help and should be expected or demanded.