Build a bank then click the "Donate On" button to prevent taxes. Move the pointer and watch the bank meter fill up. When it almost touches the end, click the "Donate Off" button to collect the bank interest. After getting the money, repeat the process. This must be done quickly to avoid paying the taxes. You will pay taxes less than when using the "Donate Off" option at all times.
Casual mode
Complete the first three levels in Career mode.
Easy money
Always flip your first house to get enough money to pay for materials, etc. For later levels, the following sequence usually works.
Build a sawmill.
Spend $75,000 on materials.
Build a workshop.
Build a bank and set it to donate.
Hire a worker if needed and build the most expensive house you can afford.
Upgrade the house to two stars if Rambler and mansion, and four stars for everything else if you can afford it. Do not sell anything at three stars.
Flip the house.
Buy materials at the cheapest bulk rate.
Hire workers and build the most expensive houses you can afford
Upgrade those houses to four stars if you want to keep them. Set the rent is proportional to the money you spend on it by percentage.