Consider this stress relief exercise –
Set a timer (for example on a digital watch) to beep every 3 to 5 minutes as a reminder to check your breathing. This helps because as we submerse ourselves into a given task, we can easily lose track of our breathing without realizing it.
You may even find it helpful to repeat a phrase during your "breath in - breath out" practice like, "I'm breathing in", "I'm breathing out", to help you establish the proper rhythm. Your goal is to allow your body to take over automatically with proper breathing habits.
Practice makes perfect - and you'll find that this is an excellent stress management technique.
Understand more about Stress Relief breathing techniques