Hi,
the only real advice is to brush teeth as you would normally do, but with braces it can be difficult.
Flossing is difficult, but as imporatnt, if not more so when an ortho appliance is fitted. pts can use floss called superfloss, whish has a stiff end that can be threaded under the appliance and teeth can be flossed as normal. It can be very tedious to do, but stress the importance of thorough OH, whilst having a fitted ortho appliance.