There are several things you can do to avoid an embarrasing stop at aiport security. Firstly, don't wear metal things/remove them when you're there.Jewellery is a no-no.Leave your laptop/large electrical items in a tray.Be careful when it comes to liquids. Place your moisturiser/mascara etc in clear plastic bags and be prepared for staff to ask to test your items,it's their job.Don't take anything like razor blades/nail clippers/toy guns for a child in hand luggage,most sharp or pointed items are not allowed.Also be prepared for staff to ask you to remove your shoes,if you stay calm you'll avoid any kind of fracas.Comply with airport guidelines about the amount and the size of hand luggage you carry,you don't need to take everything!If you've travelled by plane before try to remember the items that made you beep when you went through airport security,leave them at home/remove them when you get there.