What are some of the small amenities you think guests would appreciate which would help stand out? For me I always leave two bottles of water on the nightstand.
I don't want to give away too much of my magic sauce, but for me, I make sure I leave a way for my guests to charge their phones in my bedrooms. My nightstands have built in USB ports and I leave a charging cable out for them.
I have a drawer of menus from local restaurants in my kitchen.. I know everyone has the internet these days but there are always the clientele who are not tech savvy and I feel this is another way to give recommendations to good places in the area.
Not exactly an amenity but I have all the important light switches labeled with a label maker as well as exterior lights and certain indoor lights that are "smart" so if guests arrive late it feels more welcoming.
I leave a small basket out in the bathroom with toothbrushes and toothpaste in case anyone forgets. I get it from the dollar store so it costs next to nothing, and most of the time people don't bother using it.
In my bathroom vanity I have things you will never find in a hotel: feminine hygiene products, spray deodorant, toothbrushes, toothpaste, dental floss, makeup wipes, poo pourri, disinfectant spray deodorizer, masks, pocket tissues. All displayed and organized neatly off course.
I think it really depends on your location and clientele. If you're in the woods, providing bugspray is obviously nice. If you're in Vegas, suncreen in case they forget. You can always buy cheap travel size ones and stock them in your linen closet or bathroom.
Whenever it comes to amenities, just remember that guests will likely nitpick if you have something listed and then they expect it and it's not up to expectations. I find that gets will be pleasantly surprised when they see certain amenities not listed (like a steam ironer or snacks/bottled water) but if you list it and they come with the expectation there is a risk they may be "disappointment". It might be better off to provide it and leave it off your listing - how many people are going to decide to book your place because you have a steam iron listed as an amenity anyways?