Over the last decade or so, everything in fly fishing seems sparse, lean, smaller, lighter. Ever lighter fly rods, thinner waders, fabrics, and ever smaller fly patterns. Efficient and seemingly productive.
I am not advocating for heavier rods or clothing. But, larger, more full figured fly patterns do have their place in the fly box. Size 18 (fly patterns here) are necessary, but a size 14 (fly pattern or clothing size) is often closer to the reality of what is normally used.
Perfect your fly tying on larger sized hooks and scale down the proportions and materials to smaller hooks over time. Trying to go to smaller sizes too soon only leads to frustrations, whether dieting or fly tying.