Hey man,
I've got pretty much the same goal and same times as you, I've run 17:41 for 5k XC and 4:52 mile/ 4:30 1500m. Here's what I'm doing to get there:
- gradually, but somewhat quickly, building mileage up to 60-70mpw
I'm coming off a 3 week break from XC, last week I ran 30 miles and this week I ran 38, next week I'll run somewhere in the low 40s, all in 6 runs (one rest day per week)
- focusing on the long run and building endurance
I did an 8 mile long run this past week (I know, not very long) but I would like to build up to a long run of up to 16 miles a week or every 10 days, depending on how my body can handle the mileage
- getting better at tempo runs:
During Xc I could tempo 7 miles at 6:30 pace. I haven't done a tempo since my break, but I would like to do a tempo run every week or 10 days. I am planning on starting at 3-4 miles at 6:30 pace and getting to 10 miles at 6:00 pace by the end of the winter. I believe it's very important to develop a strong aerobic base, because it makes faster workouts much easier to handle once you start doing them.
- developing over all strength:
I am lifting and doing other supplementary core, plyo exercises 4-5 times a week. I believe in becoming all-around stronger to improve my form and help prevent injuries.
I'd also reccomend posting your training in this thread to get feedback on that. Keep working hard, stay motivated, and believe! Good Luck, and happy holidays!