1) Look at your players' best attributes and try to teach them new moves which suit those attributes, eg. if you have a very agile striker with good anticipation and acceleration, ask him to play with his back to defenders OR to try to beat the offside trap - if a striker has good strength, dribbling and flair it may be worth asking him to go around the keeper.
2) Teach your players to train in new positions - a more versatile squad makes it a lot easier when picking subs or when altering formations mid-match. Try to choose positions they already have some experience in like "arkward" or "unconvincing" rather than a position they've NO experience with whatsoever. This is a great way to save money too because you can add depth to your squad without having to recruit lots of players, who will only end up getting upset when they are not getting enough games (even as a fringe player).
3) Personally I avoid mind games but each to their own. Sometimes after losing a game though it can help to praise the opposition manager (except rival teams) because some of your players will be pleased you are diverting the attention to another team (although some players won't understand and will be displeased you are "praising other clubs".
4) Generally pay little attention to player's reactions to your press conference remarks - it has little impact on their morale most of the time.
5) Building a relationship with another manager will make it considerably easier to sign their players without being priced out of the park, but this can take time.
6) Always consider the "weaknesses" section in scout reports, and mostly the level of interest the player has in joining your club. I recently scouted a Brazilian international striker from Inter and he had "little interest in joining our club at this time" - this is better than "no interest" - as evidenced by the fact he became unsettled a month later (nothing to do with me as I'd all but given up on him" then I rescouted him and he was then very interested and how he's mine!
I could go on all day so I shan't but others on here Im sure will be happy to help further.
EDIT: One more v. important thing here: in January/February many players contracts will be expiring within 6 months so you can offer them nice contracts before their club renews theirs - great way to get great players for free - I just signed the world's best goalkeeper for FREE!! But be wary about signing too many this way as A) too many signings arriving within a short space of time is never good for club harmony, and B) you may end up having a great season and by July your club rep has gone up and you can attract a better standard of players and your bargain signings will look a lot less appealing and you'll have less room in your squad for any potential stars who may be available.