Use the following tips to complete the indicated job easier.

Courier
If you fall down notice that your character flashes briefly. When that happens, your character cannot be harmed.

Fisher
Try to catch multiple schools of fish for easy money. Wait until the fish cross paths before you throw the net.

Firefighter
Use short bursts of water to put out fires. Do not spray the water constantly.

Haunted House Crew
To get more money, change the outfit to the same color as the person you are trying to scare by pressing D-pad Left or Right.

Security Guard
Always watch the man with the Mohawk.

TV Shopping Crew
When the host throws fruit and vegetables at you to swing at, wait until they are slightly behind your character before swinging.