How can I unethically increase earnings?

Most illegal acts would be considered unethical like stealing a patent or trademark, espionage on a competitor, etc. You could cheat your customers, short ship, overbill, deny warranty coverage. Similarly, you could cheat your suppliers with false claims. You could fabricate excuses to avoid paying your bills. Or you could simply make false accounting entries based on bogus and fraudulent documents. All of these actions tend to produce short term effects. Eventually, you'll be exposed and pay the price.