Hotel room: We always bring some zip lock bags, and place things like the remote control for the tv in there for the remainder of the trip. It's less time consuming than cleaning little things like that. We also bring Clorox wipes and clean the toilet, and we wipe it down every day upon returning to the room. And we take the comforter off the bed, and it stays off the bed. Oh! And if you're a germaphobe, I would recommend bringing your own hand soap. Most hotels just have a bar of soap for your hands, and that still kind of grosses me out, because then I think that germs from the whole day are just on the bar now that you keep using. We usually pick up a nice scented soap from Bath and Body and bring that with us for the hotel room.
Parks: Bring hand sanitizer, and definitely use it before all of your meals. Wash your hands frequently (obviously you know this lol). This next bit of advice I kind of do in every day life, but it applies to WDW as well: Don't touch germ surfaces that you don't need to. For instance, I take the subway to work everyday, and if I can't get a seat I've learned to stand without having to hold on to the handrails, because I feel better knowing that I'm not touching it at all. So if you're in line for a ride, and tempted to rest your hand on a bar or handrail don't do it. Even if they get cleaned nightly, tons of germy hands have touched that before you. If you really must lean or something, lean with a part of your body that is covered by clothes, unless you plan on touching your own lower back for instance it won't be a problem. You may also want to avoid buffets. If you do go to buffets, try to go when they first open so there is less of a risk that people used their hands to get food rather than utensils. And if you touch the utensils to get the food, sanitize your hands before you pick up food with your hands and eat it.