Giggs and Neville were named to David Moyes' coaching staff this week.
Steele, who left Old Trafford this summer after Moyes decided to replace him with Everton's Chris Woods, told BBC 5 Live: "They have to develop their own coaching and managerial style.
"They may have passed the necessary coaching qualifications but it is a bit like becoming a driver. You don't become a great driver the night after passing your test. I'll be very interested to see how it evolves with both Phil and Ryan.
"You have to time to go out, practise and sometimes fail. Sometimes sessions won't work and they will have to ask 'why?' But what a great place though to come in and be able to say to David Moyes, 'can I have a quiet word?"