Easy Money:

Simply find an empty can and kick it into the nearest trash can.

Rapid Fire:

Hold Square and rapidly press Forward. This is very helpful in acquiring the Class S license, against the time consuming purple things. One disadvantage is that you will have difficulty dodging against the fast ones. However, overall this is very good against slow and immobile ones. You will not need to upgrade your energy and rapid after learning this.

Getting the Jet Skates:

Use the following trick to get the Jet Skates quickly. In the first ruin where you have to save Joe, get the old hover jets. When you first go down, take the path on the right, then go straight into the room. The jets should be in that room. After you save Joe and go to the surface, go to the Junk Shop and buy the Roller Board. Take this to Roll and she will make you the Jet Skates.

Easy Money:

Once you have the Drill Arm go to Roll and have her equip it. Then, go to the ruins on Manda Island. Find the first drillable wall and destroy it. Next, keep going forward and you will enter a room containing a large golden bird object. Destroy it to earn 6,500 zenny. Exit the room through the door at the end. Come back in the room and it will still be there. Repeat this as many times as needed.

Infinite Zenny:

Go to the snow village and look for the two trash cans. Each of the trash cans have a can that can be kicked into them. One of them is 200 while the other one gets you 1000. Be careful though because you have to wait for the message to disappear or else you don't get your money.

Get 300,000 Zenny:

First go to the Saul Kada ruins, go around where there is a man standing who sells things. Buy the reaverbot eye which cost 100,000 zenny. After purchasing it, got back to the Yosyonke town. Go over the junk shop, go to the back door, where the store owner is, and sell it!!! Bid for 300,000 only or sell it only for 10,000 zenny.