Spending your money wisely helps a lot. I never tried finding a fast trainer, I just made use of it when I happened to get one. Before buying a player, know what you want and know what you are willing to sacrifice for a more affordable price. Instead of buying 2 goal keepers and training them like crazy, you probably would be better off buying one goal keeper of better quality and allow him to grow through consistent training. Speaking from experience, players can be fast trainers and still look like a clueless sack of potatoes on the field. Never buy on impulse or on "special offers" since you will then be guaranteed to overpay for mediocre at best. Although I also did quite well before then, level 6 was the first season with the squad I really wanted and consequently the trophies I wanted too, it doesn't happen over night. Patience, work with what you have, know what you need, consistent training, and knowing why you lost are the keys that worked best for me.