Stop and breathe - take a moment to step away
Identify what is causing you stress - really think about the problem
Think about all the possible responses you could give - try not to react immediately
When you are ready, react
Reflect on how it went - what worked? could I change something next time?
Plan for furture stressors - what makes me stressed? when could this happen? what can I do to prepare?
But remember its a marathon not a sprint - take one stressor at a time
Keep calm and carry on...