You managed something pretty good here despite the high winds... I've tried taking macro shots in high wind... it's crazy annoying and you can spend a good half hour trying to take a single good shot of one thing ... bah!
Anyway!
For something as full volume as a banksia, it looks a bit flat perhaps a shallower DoF would've helped in giving a sense of its size. Also, given the deep red vibrance that banksia's can be known for, the colours looks a bit muted, but that might just be cause of the plant itself rather than anything you did (or didn't do) - perhaps increasing the contrast in post?
The composition and contrast has my eyes wandering towards the central black area of the flower yet the view doesn't really let you see much of it - perhaps a more frontal image, still angled looking upwards at it to continue showing the volume of the banksia, but permitting a more fuller view of its center.
And, that's all I can think of for now
Keep it up and keep practicing!
I wish there were banksia's like that around my place. I always think they're awesome plants!