i have the perfect town :-)
what i have in my town is around 20 public work projects
the beautiful town ordinance helps a lot to keep wee.ds away as well as to keep flowers from dying (actually they never die)
also i didnt know this but fruit on the ground counts as "trash" so i went around and picked everything up
i think you also need to have the cafe, police station and final upgrade of timmy and tommy nook's department store
to get the cafe (you probably know this) you need to donate at least one thing of each category at blathers museum
then a "..." thinking bubble will appear over his head
he'll give you a public work project a complete the second floor to the museum
after the second floor is completed another "..." thinking bubble will appear over blathers head and he'll suggest to build the cafe for brewster as a public work project
the police station is recommended by a random villager
you get the final upgrade you have to complete 4 of gracie grace's fashion checks
hope this helps!!!

to get* the final upgrade oops

im not actually sure but hannimal crossing's advice seems pretty good! you could also look online im sure theres something

-water the flowers, ESPECIALLY the dy.ing ones(3 times each to make them sparkle)
-talk to the villagers nonstop
-do what the villagers tell you to do(ie if they ask for new furniture, fruit, bugs, or fish, give them what they want, or make their deliveries for them)
-plant lots of flowers
-donate to the museum whenever possible
-send mail to the villagers
-post on the signboard next to the train station(I posted "the game" on mine while trying to get a perfect rating)