Increase reputation
Create a syndicate and find jails (large red/brown and pink buildings with bars) in all the cities. Click on the building and the "Jail" column will appear. Click on the first picture at the top to get the men to help with the mission. Kill the cops and get some people out to increase your reputation.
Easy clean and dirty money
After starting a new game, start your own syndicate. You can choose to rob a bank, and by doing this by yourself you can get around $50,000 dirty money. You can choose to keep this or launder it. By laundering enough, you can drive the rate down to about 6:1 or 7:1. That means that instead of 20 dirty for 1 clean, you get 6 to 7 dirty for 1 clean. This is an excellent way to get money immediately.
Invincible thugs
After starting your own game, join your own syndicate. Select your branch. Go to "Employees", and select "Security Guards". On the right, you can select a Thug, Burglar, etc. Select your Thug, hire him, then look at his stats. You can choose to beat him until his health refills. Do this a couple of times, then send him on his own mission. He will have an icon above his head, like an anvil or something else, and he will not take damage.
