If the butterfly is stationary, basking in the sun or nectaring on a flower:
If your butterfly is moving:
Even a photo from quite a distance can be enough to clinch an ID. If the butterfly is cooperative, it can be helpful to take both the upper and lower wings as these might have diagnostic features that separate very similar species.
Take your first photo from a distance before getting closer
This technique works well - one foot forward and slowly lean towards the butterfly
Please also refer to our Code of Conduct