how to get perfect town without hacking

A town is considered "perfect" when it has the game's required number of trees and flowers spread evenly throughout. You can check the status of your town at the Town Hall.

Steps to make a perfect town
1. Use a shovel* or patterns to make acres by 16x16 shovel spaces (16 down, 16 across)
2. Have between 12 and 15 trees and 6 to 10 flowers per acre in your town.
3. Try to get rid of all the weeds in your town.
4. Don't leave any items lying around. Seashells and fruit are excluded from this.

*Note that holes made by the shovel will disappear when you save. If you want to keep a grid up for the 15 days it takes to get the Golden Can, you're better off using patterns. Also, if you use a shovel, it can make it harder to travel from acre to acre as you cannot walk over holes.

Each weed or non-natural item (anything from random furniture to rotting garbage) effectively cancels out one flower in the 16x16 area it is in. (Confirmation needed, but that's how it worked in GC and WW). Buried items (excluding fossils and gyroids) can also have a negative impact; a buried rotten turnip has as much negative impact as an unburied rotten turnip, for example.

A good way to help keep perfect town is to buy all the flowers from Nooks every day and plant them where needed. This is also a good way to get the silver can which can help make watering your flowers faster.

If your town meets these specifications for 15 days in a row, you earn the Golden Watering Can from the Town Hall's environment counter as a reward. Once the Gold Can has been earned by one player in your town, any of the remaining three players can obtain one (regardless of whether or not they helped). (Make sure if multiple members of your town want one you keep a perfect town until they all have one.)

In order to have a perfect town, 8 out of 25 acres must be "perfect," and the rest must be "decent." Here is a guide on how to make perfect and decent acres.

"Sweeeeet" ("Perfect") acre results:
0 trees and 27 or more flowers
1 tree and 25 or more flowers
2 trees and 23 or more flowers
3 trees and 21 or more flowers
4 trees and 19 or more flowers
5 trees and 17 or more flowers
6 trees and 15 or more flowers
7 trees and 13 or more flowers
8 trees and 11 or more flowers
9 trees and 9 or more flowers
10 trees and 7 or more flowers
11 trees and 5 or more flowers
12 trees and 3 or more flowers
13 trees and 3 or more flowers
14 trees and 3 or more flowers
15 trees and 3 or more flowers
16 trees and 5 or more flowers
17 trees and 7 or more flowers
etc.

"Fantastic" ("Decent") acre results:
0 trees and 21 or more flowers
1 tree and 19 or more flowers
2 trees and 17 or more flowers
3 trees and 15 or more flowers
4 trees and 13 or more flowers
5 trees and 11 or more flowers
6 trees and 9 or more flowers
7 trees and 7 or more flowers
8 trees and 5 or more flowers
9 trees and 3 or more flowers
10 trees and 0 or more flowers
11 trees and 0 or more flowers
12 trees and 0 or more flowers
13 trees and 0 or more flowers
14 trees and 0 or more flowers
15 trees and 0 or more flowers
16 trees and 0 or more flowers
17 trees and 0 or more flowers
18 trees and 3 or more flowers
19 trees and 5 or more flowers
20 trees and 7 or more flowers