We do offer extras, but Airbnb makes it hard to charge for them (HINT! HINT!) 2 of the popular ones are a comfy extra bed when they bring a 3rd guest. We have a "unique stay" in a yurt with one king bed. If they bring a 3rd guest it's already a $10/nt add to cover water, cleaning, extra dishes), but for an additional $10/stay we set up a twin and arrange the furniture so it fits.
Also, due to our glamping type of experience, we only have a BBQ and BBQ utensils available, as well as coffee maker and toaster. If they want a full outdoor kitchen set up (2 burner propane stove, pots, pans, mixing bowls, etc) we offer it for $25/stay. We used to include it but found either most people ate elsewhere and didn't use the items so they just got dirty, or they had no idea how to use an outdoor kitchen and were running the items. This allows us to set up the kitchen and give a tiny bit of instruction on use. We also know what to clean afterwards.
Lastly, we offer doggie day care. We allow pets but during the summer it gets very hot and people can feel stuck because they can't bring their dog to restaurants. Sometimes it's even too hot by the river. So we set up dog runs and offer to care for the dogs in the shade well they enjoy the many hikes that don't allow dogs (California US State parks).
Separately, we do have an outdoor pizza making experience and a wine making experience offered through "Experiences" since that is finally available in our area.