I've been playing on and off since last August and my newest project to keep myself interested in the game is to try and achieve the perfect town rating (i want that flower clock!) but have no clue how to go about it...
-have between 110-200 trees (I planted 10 of each fruit tree to keep count)
-have at least 50 flowers
-no weeds
-no garbage
-little to no items on the ground
-PWPs
The guide I showed you specifies which PWPs are good vs. bad for perfect status. I'd also suggest enacting the Beautiful town Ordinance so that flowers don't die and weeds don't grow. Once you have enough flowers and trees it's just a matter of building PWPs and asking Isabelle each day about "Citizen Satisfaction" until she says it's perfect.
Basically planting a lot of flowers and trees helps a lot. I don't think you get penalized for having too many trees in this game like you would in the previous games. Also, I think you have to have the campsite and cafe built. I had a lot of PWPs, but Isabelle kept telling me my town needed more PWPs. When I built the cafe, I had a perfect town the next day.