You'll then be able to select to use the free bets through using the 'Use available bonus' toggle at the bottom of the betslip. Enter the stake value of the free bets you wish to use in the normal place and proceed to toggle on the bonus (Free bets can be used to place each way bets via desktop and mobile channels.
Some traders spend hours each day analyzing data and placing bets, while others may only trade part-time. The more time and effort you put into Betfair trading, the more potential there is for you to make money.