Not everyone would want to do as I do, but I use gray synthetic yarn for my wings.
Olives in my neck of the woods are 20s and 24/26s. At those sizes they're hard enough to tie without getting fancy
With a poly yarn wing, you can tie it in as usual and then trim to size as the final step
The fish like 'em fine that way, just don't expect to show them off to your friends.
If you're using feathers, don't waste expensive dry hackle, softer is better and less likely to spin the tippet.