Usually for purely aesthetic reasons I imagine anthro barn owls with gryphon-esque features. For example, instead of having hidden ears I'd opt for long feathery tufts. Instead of coal black eyes I'd imagine only darkly tinted eyes. Instead of a rather discrete beak I'd imagine a more protruding hawk-like one, with a more angular head shape. Instead of arms that are purely feral wings, I'd imagine human-like arms with downy feathers and scaled hands, with long wing feathers trailing underneath. Also I'd exaggerate the 'baggy pants' thigh feathers of the barn owl, rather than smoothing everything out.

Here's two examples of female anthro avians, for future study: a Snowy Owl, and a Red Tail.

...Over all, not bad though!

I'd appreciate if you didn't tell me exactly how to draw what is essentially my decision in terms of stye, but this was a long time ago and I'm still developing my style and how to combine the anatomy. I will keep this for future reference, and I appreciate that you took the time to give me some in-depth feedback.