I've been playing this game for 4 years and I always see these monsters with 500 in everything. I was wondering how you train these monsters so well? What training methods do you use and everything?

Most of us can max out our monsters to have 999 in 2-3 stats and 6-800 in the others (if you use the never tired method, then you can max all 999). Training methods are already described in this area. You need to have incredible coaches as well.