Miss Giraffe has great ideas for teaching reading fluency. I rarely place things on this site that cost money, but Miss Giraffe is generous her ideas on this site, and she has packaged several units for those who want to spend minimal time prepping for these lessons.
Disclaimer: The ideas are available for free, but the bundles are purchased on Teachers Pay Teachers by clicks on the links towards the top of Miss Giraffes’ website.
Here are some of her additional reading posts:
Short A Activities (usable for any sound)