Tactics are personal preference, I favor a possession based game and prefer playing with one striker. I hoard midfielders also...but that's just an FM thing.
Tactic – 4-2-3-1 Wide
I generally do not change my formation before the match, unless I'm playing a significantly better team. Though, if better opposition plays a 4-3-2-1 with a defensive midfielder, rather than an advanced playmaker, I am more inclined to match their formation. If the better team has a man in front of the defense, it's almost foolish to try and take that head on from the start.
My Team instructions will generally look like the above image at the start of every game.
Against significantly weaker opposition, I'll choose Attacking mentality. Against similar strength opposition at home, I stick with Control, away from home I might adopt Standard before switching to Control. Against the top sides at home I keep the Control setting, away generally I set up on the counter, home or away, I limit Creative Freedom, selecting Be More Disciplined.
Team Shape
I always have Flexible for Southampton. I would like to select Fluid, but I think it allows almost too much creativity. If I were playing as a top side however, I would definitely select Fluid.
Team Instructions
-Retain Possession
-Shorter Passing
-Work Ball Into Box
-Exploit the Middle
Substitutions
Around the 60 minute mark is when I make changes. However, if a player is doing really poorly, a rating below 6.0, I'll sub him at halftime usually.
Opposition Instructions
Vary from team to team. The one constant is I ALWAYS (from FM13-17) close down the fullbacks. I'll close down anywhere from 4-6 players, depending on the strength of opposition.
General Play
Key to how my Southampton side play are the Fullbacks, always on Attack setting, set to getting further forward, and putting in crosses. The Deep Lying Playmaker is always in a Defensive role and whoever partners him is the Advanced Playmaker, in a supporting role. That being said, against top top sides, I play both midfielders as DLP with Defensive setting. Wingers aren't always wide men anymore, so usually the AMR and AML, are inside forwards, in the Support role, allowing room on the outside. The AMC is usually with the Attack setting and More Risky Passes as he's the main creative force. The Striker is always on Attack setting and I prefer Advanced Forwards, Complete Forwards, and Poachers. There are always only four players with an Attack role - both Fullbacks, the AMC (the attack setting can rotate between the AMR and AML, but generally it is the AMC), and the Striker.
Scenarios
1. Winning against superior opposition with 30 minutes to play
Deciding when to switch to a Containment strategy is the toughest. I try and resist as long as possible, but around the 80-83 minute mark I select Be More Disciplined and Stick to Positions. I've been burned many times for switching to early.
2. Losing by 1, with 15 minutes to play
Attack mode by now should have already been selected. It's around the 75 minute mark that I will throw caution into the wind and select Overload. I love Overload. Tempo is pushed to as high as it will go and Closing Down is at the highest setting. Opposition settings are crucial here, close down the midfielders in an attempt to get possession back. I've had quite a bit success in scoring late goals, but I've also been done on the counter, so it goes both ways. This also applies when drawing against a team you should be beating.
3. Playing with 10 men
We've all been there with the straight red or the double yellow. It's never convenient, as often it is a defender who is sent off. You should have at least one CB and one FB on your bench, minimizing the chance you have to play someone out of position. Then, I take off the AMC and replace him with someone who can play the DM role.