Increase reputation
Build a syndicate and locate jails in every city. Then click on the building and the "Jail" column will be shown. Click on the first picture at the top to get the men to help with the mission. Now kill the cops and get a few people out to raise your reputation.

Invincible thugs
After you start your game, join your own syndicate. Now select your branch. Go to "Employees", and select "Security Guards". On the right, you can select a Thug, Burglar, etc. Now select your Thug, hire him, then look at his stats. You can choose to beat him until his health refills. Now do this a fewf 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 receive any damage.

Easy clean and dirty money
After you start a new game, start your own syndicate. You can select to rob a bank, and by doing this by yourself you can get about $50,000 dirty money. You can also choose to keep this or launder it. By laundering it, you can drive the rate down to roughly 6:1 or 7:1. This means that instead of 20 dirty for 1 clean, you get 6 to 7 dirty for 1 clean. This is a great way to get money right away.