Although boring as heck, I always found pool running to help. Just one or two 30 minute sessions for a few weeks should help. But with the resistance of the water, I would stay away from the water 7-10 days before a race so muscles are recovered.
Uphill strides can help correct form. Both in pool and uphill running your body will want to work as efficiently as possible so your form will improve.
Finally the drills are good, but plyometrics will increase your power and you'll improve your economy. Just need to be careful with plyos in that you start with a light session and each week progress with the number of jumps and more advanced jumps. Eccentric training in general will increase your power, so downhill running if you do not want to do plyos. I try and do hill workouts that add in a lot of downhill stuff like hill cycles where you find a 1- mile loop that is mostly gradually downhill and has a a steep uphill that lasts about 70-90 seconds and you run the whole thing at lactate threshold pace. So on the downhill part your effort isn't LT effort but on the uphill to stay at LT pace your effort will probably bring you near 1 mile effort. You run this loop nonstop for 20-50 minutes making sure you DO NOT run the downhill too fast because it's easy to do and an easy way to get hurt. Camel humps is another good one where you run up and over a hill that is 3-6 minutes total trying to run the same effort both up and down. This is more interval based taking 1-2 minutes rests and going back and forth over the hill anywhere from 2-8 times. Good thing with this is you get both sides of the hill so different grades going up and down when you turn around and run back up and over.
Some weight lifting might help. Pawback for hamstrings with either cable or bungie will teach you to bring you feet back to the ground quicker, making you more efficient.
Enjoy