To be honest I don't understand how anyone can win any games without doing extensive player scouting for each individual team. I get it if you choose the same team every season, but even then, every time you start a new save there are a LOT of "random" attributes that change how a player is in several ways with different with every save. So in some small degree, you'll need to keep an eye out for these, but more often than not these are hidden and unrelated and the reason I've mentioned it is because winning has nothing to do with having the best of everything. It just doesn't.
I've yet to find a tactic as good as mine on the forums. Too many of them are too specific and I can see the AI finding a way to defend against it or counter it or whatever. Whenever I tend to lose it's because I haven't paid attention to a substitution I've made or a tactical change I've made myself. Not because the opponent is better. And more often than not with "stock" players. Every player who goes Arsenal often sells or doesn't use Arteta and blames Wilshere for being injury prone or card prone. I got Wilshere and Arteta to play +30 games in my first 2 seasons without a single card. They were also getting avg. ratings of above 7.20 a season which is amazing for a central midfielder not scoring or creating many. Their passing stats were impeccable. Why?
Who knows. I pay attention to everything though. If a player performs badly but the team doesn't then the next game I make sure I speak to him assertively and make sure I expect a performance, look at the result, if I get a reaction then I know I'll get a performance. If I don't get a performance and he's reacted I know he gets easily complacent so I never make that mistake again. Sometimes "better" can be worse. Don't send players out "happy" if it's an important game and the same goes for don't send players out fired up against opponents lesser than you. It just doesn't work or at least in my experience with the squads I've had.
Which goes to my last point... it's such an individual thing how you approach this game! And approach is linked to results. I noticed one dude was losing his games because he kept sending his assistant manager for press interviews and they'll respond with a tactical giveaway?!?!!? That's why I always make sure I take every interview and do everything otherwise if something happens I tend to go crazy trying to figure out where it went wrong.
Also always consider the stature of your club and players. Super important when speaking or dealing with media or players. If you're playing a better or worse team speak to them differently and same goes for different personality types.
Always praise/warn after every game or if you notice it's having a negative effect stop. Negative effect meaning if you praise him and the next game he doesn't score? Leave him alone the next game. If he doesn't score again blame his form.
If you have TWO options (i.e. players playing good form but bad last game) always choose the "BAD NEWS" option first. Blame his last game just in case he disagrees then you can praise his form and just like real if you give them good news later all they'll remember is the good news ;-)
Make sure you have a finite balance of training, rest and match periods.
Training in itself is broken into three categories and the match and rest periods are preassigned so work training AROUND your schedule. Start of the season always look to learn your tactic ASAP which means more match training, NO individual training and decent level of team training. Then when the matches start or players learn the tactic quicker (as you stay at the club longer they'll learn the tactics quicker in the off-season) begin to drop the match training and introduce the individual training. Also make sure that you have at least 1 training session before every match otherwise the match as a "set in stone" rule. Go to the calendar screen and even if you don't know how to adjust them off the top of your head look at the coloured squares and adjust all settings till you get 1 full box before every game. Anything less is unacceptable, anything more is pushing it and you can focus on better areas especially individual focus or tutoring or NOT resting a player.
No one does this? But right-click on a player, go to the "training" tab and choose "rest" you have the options of 1 day, 2 days, 3 days or a week. Use this for players coming back from injury or players who are tired after games and you're not able to provide them with the adequate number of breaks through training (this way you don't have to keep changing your training methods). This helps with the larger European clubs such as Arsenal who play every 2-3 days and also helps keep injury prone players ON the pitch.
You don't have to hire the best staff but if you do remember that their adaptability MUST be high or they must speak the countries language if their full effectiveness is going to be felt.
Same goes for players. Don't just buy players because they seem better. The other side of the grass is not always greener! Though sometimes it definitely is and finding that balance is exactly why I love this game so much XD
Enjoy ******* and remember... football > everything else.