Easy gold hints:
-Upgrade your storehouse and car as soon as you can.
-Do not waste money by overwatering grass. Instead, use timing to water efficiently. Once your well is upgraded to the maximum it will irrigate the grass.
-Sell your unneeded animals in the early levels for gold.
Repeat the early levels to earn stars to upgrade your items.
-You cannot grow grass when you run out of well water. As soon as the well runs dry, purchase more water. By doing this, the water will be ready when you need it.
-Avoid watering full-grown grass, as it is a waste of money. Do not forget to grow some if you are running out. Animals will die quickly without grass to eat.
-Upgrade your well to the maximum level and it will take care of irrigation for you, alleviating your need to deal with growing grass (and potential starving animals).
When growing grass, grow it toward the bottom of the clearing. Bears will appear at the top of the screen and any animals in range will be lost. Animals will wander around the full area and return to the grass periodically to eat, keeping them away from newly approaching bears.
As you progress in levels, purchase cats. Cats collect items the animals produce for you, allowing you to attend to other duties. They are very helpful on levels that get frantic quickly.
Purchase dogs when you have the funds. They will keep bears at bay, protecting your valuable livestock. Losing a necessary animal can cost the silver or gold bonus.
Process as many raw goods as you can. Processed goods such as egg solids, baked goods and spun wool generate more money than raw "materials" like eggs, wool and milk.