In response to a comment about this one on my Facebook page, I realised that I'm not as attuned into 'seeing' high-key possibilities when composing a shot as I think I should be. This, to my eyes, was a fairly obvious one and the photograph was taken with this outcome very much in mind.
Probably just need to get out there and be thinking 'high-key' (or 'low key') at a more conscious level.
Interested to read whether you think I went the right way with it.
40D, Sigma 120-400 F4.5-5.6 APO DG OS @ 198mm. ISO 800. 1/1000@f5.6.