Well besides the usual running out with towels to nab a sun bed that is....
I've noticed over the last few days that quite a lot of people take two pool towels each (no one supervising, they're just wheeled out). They then arrange them on the sun bed so that they don't have a square inch of sun bed showing. Maybe their skin is too precious to be exposed to the naked plastic, metal or mesh? 
That's bad enough as newbies like myself (in the early days, I've been here for nearly a week), don't stand any chance of getting a towel for at least 24 hours when they arrive.
But, there's also a new spin on the claiming of sun beds - some people are using the two towels to reserve themselves one sun bed in the sun and another in the shade.
I have to say I've never seen either before. And before anyone asks, the hotel I'm staying at is multi-national, so no element of any one nationality being involved.