First, go to a friend's town with the item(s) you want to duplicate. You can be connected locally or through the internet. Once you are off the train and in your friend's town, go outside, and drop the item(s) on the ground. Once the item(s) is on the ground, have your friend press Start, and choose "End the multiplayer session." The game will show you are leaving, and then the save screen will be displayed. There is a small circle icon in the lower right corner at save screen. It will begin rotating, starting at the top of the circle. Let the circle rotate once, then immediately press the wireless switch on the side of your 3DS. You must do this with perfect timing, as you can lose the item(s) if you do it too soon or you will not retain the item(s) if you do it too late. Once the switch has been pressed, you should get a Resetti screen. Then, you should be back in your town. If the glitch worked correctly, you should still have the item(s) in your inventory, and the item(s) should also still be on the ground in your friend's town. Repeat this process as many times as desired to duplicate any items. Note: It is recommended you first try this trick with an item you do not care to lose until you get it to work correctly.
After you have had seven cups of coffee from The Roost, you can get a part time job by talking to Brewster while standing at the right side of the bar. The part time job is a mini-game where you must serve coffee to villagers and special characters. Typically, three villagers (not always from your town) will ask for coffee, Each animal has a preferred combination of coffee beans, milk, and sugar. If you make the customers happy, Brewster will reward you with coffee beans to take home, as well as rare furniture items. If you do well over time, your rewards get better and better until you get a rare set of Brewster gyroids. Here is a list of the rewards in the order that Brewster will give them to you.