It's no secret that Bells are easier to come by this time around in Animal Crossing: New Leaf. But, it's out of necessity that you may now load down your dirty little pockets with riches. Between your home renovations, all the things to buy, and now a whole town to run (by yourself because don't think for one second that one of your lazy neighbors will ever fork over a single bell to help out). It had to be easier to get rich or you'd never make any progress. By this point, most people know that the island is the fastest way to make a lot of Bells thanks to your palm trees playing host to a whole mess of rare beetles. But, there are "tricks" to make your beetle hunting playground all the more effective. Allow me to show you.
1. Skip the boat ride. Riding with Kapp'n in his boat is fun the first few times you do it. He sings you a catchy tune and you're quite content to just ride along. It gets old though so keep hitting B and it'll interrupt his song and take you straight to your destination. Don't worry, it doesn't affect your relationship with him even if he does get a little put off.
2. Clearcut the center. You know all those pretty flowers and trees in the middle of your island? Get rid of them. All of it. Cut it all down. Borrow a shovel and axe from your buddy by the door and make the entire center of the island bare. Why would you do this? Because, in order to catch rare beetles, the game must have "space" for them to spawn. All those flowers and trees spawn less than wanted insects and they're taking up the space the game could use to spawn the good stuff.
3. Dig some holes, lots of them. Going on the same rule as above. You want as few non-rare bugs spawning as possible. So, to help that along, dig holes. Take your shovel and make the entire center of the island one big mess of holes. Why? So there's no room for grasshoppers and/or locusts to spawn. Now, it's important to note that the holes will repair themselves if you save and quit. You can come and go from the island as many times as you need to but the minute you save and quit, you'll have to re-dig all those holes again.
4. Take away a few palms too. This is totally optional and personal preference but I removed the palm trees on the bottom half of my island. This way, I can look up the beach and see if there are beetles on the palms. Since these beetles tend to fly off at the slightest hint of quick movement, it lets me see them first.
5. After 5pm. Most people should know this but those wonderful beetles don't come out until after 5pm. Same goes for sharks. So, prep your island a bit early then put your 3DS in sleep mode until it's time for some beetle hunting. Also, if you're walking about and no beetles are coming to visit, go into the hut and come back out. It resets what's out there.
These tips will maximize your beetle catching time but will make your island quite ugly. So, it's up to you to decide how important a swift Bell run is compared to an attractive island.