I've started to get a creaking from what I think is the headset (on the rare occasion ) when I get out of the saddle on a climb and start "rocking" the bike.
It's only recently started to manifest and I'm wondering a) What could be causing it?, and b) What can I do to stop it?
Have you checked the handlebars / brake levers and other bits that are exerted to those different forces when you are out of the saddle are appropriately tight / clean?
Have you took the headset to bits, cleaned / greased it and put it back together again?
As suggested, took the headset out, cleaned, greased and reinserted. Also took the quick release skewer out of the front wheel, cleaned and greased all bits. Bingo!
First time I've ever done that. Every day is a learning day
) when I get out of the saddle on a climb and start "rocking" the bike.