You can initiate Private Trades or send money as a private person via Dashboard » Private Trades or via your company's management page.
Sending money is fairly straight forward: just click the "Send Money" button, enter who you are sending to and how much in which currency. The money will instantly be transferred, without need for approval from the receiving entity.
To initiate a new private trade press the "New Trade" button. Enter the recipient details, the thing you want to trade and the price the peer entity has to pay to receive the goods. Once the trade has been initiated the receiving entity has to either accept or decline the offer via their own Private Trades page. Some limitations apply to private trades: land with active renting contracts or retail store offers may not be traded, non-holding companies may not receive company shares and private persons may not receive items from companies.