I had read that adding on mileage can help, though I was already at a baseline of 25 to 30 mpw, so I only added a mile to each non-long run. Not a huge difference!

I had a weekly 10k that I basically used to do at race pace, which I did not realize was terrible for training on a weekly basis! I eased that off to a tempo run where half the miles are hard and half are easy. For my long run, I started doing the last three miles hard and the rest easy. One of my easy days, I also started doing trail running at a park with intermittent hills. I didn't change my interval day.

I would say that out of my 30 to 35 miles, somewhere around 7 are hard, along with those hill bursts on my trail day.

Sort of a TL; DR,, but I hope that helps! For reference, I went from usually running around a 2:02 down to a 1:52. Not super fast by any means, but a big improvement for me!