Stage 1 : Follow butterfly 300 yards backwards and forwards across field. Climb over electric fence to next field avoiding electrocution if possible. Clamber back over fence when butterfly decides the grass is greener in first field.
Stage 2: When butterfly alights on flower, throw yourself down onto your belly* and crawl commando style until you are 3 cms in front of it.
*Note: If field is full of thistles and stinging nettles, choose the nettles (less long-term damage to aforementioned belly).
Stage 3: Aim, compose, focus and press the shutter in the 1.5 seconds you have left before butterfly takes off again.
Stage 4: Check camera to see if butterfly is in photo
Stage 5: Repeat all morning if necessary.