Step 1) Grab any sunglasses (vintage is best and interestingly shaped)
Step 2) Put up exposure on flash
Step 3) Be teenagery
Step 4) Sexual innuendo it
Step 5) Caught in the moment
That's all there is to it. It helps if you have an exam soon and are procrastinating. It also helps that your mum is disappointed in you for not watching the Rugby World Cup final and therefore to retaliate you become over productive.