@Tactician I won't do that always, actually I was desperate to win the league, so...
And I don't have injury problems; never had them tho. I don't sell any player for injury, as I have a decent amount of reds. Also, I only heal them if they're irreplaceable or they've been injured for more than 3 days.
I don't buy scouts too; most of my players have been playing for the past 4 seasons. I buy high quality and young players from the transfer market who can serve me for 5 seasons. I don't bid aggressively, and I also look at the negotiations list if I can get a required player.
What can be best for you: aim Top 3 every season, don't buy tokens or scouts, put a lease on your bidding (say till Round 5), and don't be frustrated to go trophyless. Don't spend injury packs on injuries less than 3 days.
I probably haven't experienced your game, so I can't feel much from you. The most for me is continual choking in the league.