Step 8: Hand luggage
For this reason, I like to use soft holdalls or backpacks as hand luggage which can be mushed around to fit through the hole in the X-ray machine. If it doesn't fit through that hole, it can't go on the plane. I also take those drawstring bags too to carry things around during the day and they fold up nice and small.
If you're only travelling with hand luggage, the EU has restrictions on liquids that are taken onto the plane and only allow liquids in containers less than 100ml in volume. This applies to ALL liquids, shampoo, toothpaste, contact lens fluid. Fortunately they make small bottles for just this purpose in stores such as Superdrug, generally the more popular brands. These must be placed in a clear plastic bag and presented separately to your hand luggage. The European airports I have been through offer regulation bags to put your liquids in if you don't have one.