This question is a bit tricky to answer, because it really does depend on the type of laser. For non-ablative lasers, or lasers that do not create any tissue destruction, there is very little you need to do in order to assist recovery. I would say, wear sunscreen, keep your skin well-hydrated, and you should be on your way to a quick recovery from any non-ablative laser or non-destructive laser treatment.
There are some lasers that we use where we intentionally try and create some tissue destruction. These are called ablative lasers. Ablative lasers are much deeper and fiercer. There's special care required post-laser to make sure that your healing process is optimum. I would certainly ask the laser operator for those specific instructions. For ablative lasers, they typically involve some post-laser antibiotics to prevent infection, and oftentimes some anti-viral preparations to prevent a viral outbreak as well.