After having an obsession with skies, I think I may have conquered it now. I've painted them with fabric paint, I've machine quilted them and now I've used a technique that has satisfied me. I read about using thread waste - all those little bits of coloured thread you cut off from your sewing and embroidery - and I machine quilted them on to this sky, which I made by appliqueing "sky" shades onto a foundation, along with a few seagulls cut from the beach/lighthouse fabric. I had to cover the thread waste with Sulky water-soluble stabiliser first as they kept catching in the darning foot I was using; that worked and when I'd finished machine quilting I just dipped it into water and the Sulky dissolved. Here are some close-ups to show you how it looks.
I hope it gives you some ideas for yourself.