I have been a host for more than 5 years, a superhost for more than 2 years. I take my job seriously and take pride in the work. My tips for getting good reviews as follows:
1. Be sincere. Be present. Be empathetic. From the listing page (accuracy of photos, clarity of description) to the first message you send to respond to an inquiry (upbeat, personable, positive), pay attentiton to how you communicate. Learn to read people (some like lots of attention, others like to be left alone). Put love into it!
2. Cleanliness counts. Make a list of all the things to do for regular cleanings (e.g. change sheets, clean bathroom and kitchen, vacuum everywhere,etc), and a list of "special" cleaning things (deep-clean fridge, wash windows, launder curtains, etc). Special cleaning things are the things you'll do 3-4 times/year. Use your list as a checklist for yourself or your cleaner. Be organized and keep to a schedule. Use natural products, with essential oils, to keep things smelling fresh and good.
3. Be responsive. Answer messages as quickly as possible. Keep it simple. Try to anticipate guest needs (if they have a child, offer a few neighborhood ideas for playgrounds and activities, for example).
4. Go out of your way. Hospitality is all about giving of yourself. Leave a little welcome treat (ideas such as free subway pass, breakfast items on hand, a bar of local chocolate, etc).
Show your guests you really care about their happiness and comfort. I promise you will consistently get good reviews if you do this! Of course, there are a few people you cannot please. Don't take it personally. Just keep doing your job well and WITH LOVE.