My rear spokes seem to be creaking which I presume means they need tightening?
Should I just go round the wheel and give them all a half turn, or is there a more scientific way of going about it?
Cheers.

I’d identify the cause of the creaking first.

If it is a Hope Pro 2 Evo rear hub then have a look at the two inner bearings in the free hub.

Also look for cracks above the spoke holes in the hub.

Is the QR tight ETC ETC

QR first, grease and tighten. Twang spokes & u’ll soon see if any are loose

Another possibility – I had creaking wheels and the LBS recognised the issue. Dribbled oil around the holes where the spokes attached to the hub and that creaking was gone.