@Julie Hill your management company should be able to answer all of those questions for you since they should have experience in your area. What type of marketing you do totally depends on where your rental is located and how big your PM company is. I have heard of individuals crushing it with Facebook marketing, simply paying to advertise a link to their listing on Airbnb or VRBO. Ask your PM company if they can run ads for you, although most of them don't really bring value with marketing unless they have a large following and get a lot of direct bookings.
-Tricks for decor/amenities: A hair dryer can add $10/night . Also ask your PM company to leave out coffee, snacks, and tea for guests. Ask them to survey guests to figure out what is the best bang for your buck. I do this by using software that sends a survey out to every guest post-stay.
-Websites: Your PM should use software that allows them to take direct bookings. The larger the company generally the more of a following they have. Also depends on the area and what platforms people are using.
-Advertising: Google Adwords and Facebook have proven to be most effective. Make a page just for your listing on Facebook and promote it. It will show up on google searches when people search for things like "where to stay in X town"
-Videos: We don't do videos because they generally cost way too much. Airbnb screens out all links, VRBO allows them, and I am unaware of other platforms that allow URLs to youtube pre-booking. Instead, make a free floor plan of your listing and post it as one of the photos.