I was initially introduced to Football Manager by my brother, he had already been playing it for some time and recommended it to me quite often.
I was already fully delved into FIFA on Xbox for a long time, you needed a crowbar to get me off it, anyway one day I was playing FIFA career mode and I said to my brother in a passing comment :

"You know what, I really like career mode (manager) but I wish there were more specifics, you know like tactics, pressing play, tightly mark, player emotions (properly) etc, etc"

It was something EA did do with FIFA, just very vaguely and not at all that detailed.
My brother took this into account and replied :

"Honestly, it sounds like you'd probably like playing Football Manager, if I were you I'd give it a go"

So I did.

At the time my brother was playing Football Manager 13, so I downloaded it.
My first save on it was with Liverpool and that is where it all began.
I loved every second of it, especially when my brother downloaded a mod for me that was "FM Base" - a completely wiped clean team, with its' own stadium and staff and 200 million pounds, the idea was to build from scratch; get in your own players, more staff you need, fresh tactics, youngsters, you get the idea.

The experience was frustrating, but very enjoyable.

I went on to play 13 very heavily, then when 14 was coming out got it a month early, and now 15 is out started playing that a week early before release.

Now to what i've learned....

.... As you can imagine across heavily playing, many, many, many different saves, tactics, trial and erroring, plus lots of help and guidance from my brother - I have found the most solid formations, players, tactics and much more. Depending on your players and team, amongst others, I can't give specific tactics to be wonderful to everyone, but I sure can give the solid foundations for success.


Now for the list :

- Staff.
Staff are a lot more important than anyone will realise. If you have a shabby assistant manager, you will have a much more difficult time managing. That is one of the first staff I sort out before I even start a season, look at staff in search and find one with good motivating, tactical, mental, man management, tactical knowledge, adaptability, determination, judging player ability and technical, with possibly fitting in attacking and defending.
Remember you won't leave ALL tasks to him, but as someone to help you in matches and mentality for your team, he will be important.
When we think about discipline etc, that is up to you, same goes for team talks, and as for working with youngsters, trust the head of youth for that, you want to assign the right tasks to the staff that are fully capable and suited to the job.


- Formations.
There is no "right" or "perfect" formation. It obviously all depends on your players and tactics - but there are certain positions I personally find vital for success. You DO want to make your formation suit every single player you have on the pitch 100%. If, for example, you have Luis Suarez who is naturally a striker you CAN play him right-wing, but no matter how well he does there he will not be anywhere near as effective as he is striker.
Summed up - strikers as strikers, center backs as center backs, center mids as center mids. Buy players accordingly.


- Holding Midfield (CDM)
One of the first things my brother told me was to have a CDM in my team, a ball winner, a tough-tackler. After a few years of chopping and changing around, with ridiculous amounts of players, teams, staff, formations and tactics, I can only thoroughly back my brother up on that bit of advice.
It's as simple as if you go all out attack and it works very well, you will end up like Liverpool in real life during the 2013/14 season - prolific, even winning matches, but leaking goals.
If you go the other way to extremely defensive with two CDMs - you will barely score or just spend all and every match defending for a 0-0 unless you squeeze a lucky goal.
The trick is control and a balanced looking team.
One CDM is enough, you may want a CM too, as long as someone is backing up the defence, you have a fluid midfield and you are scoring the goals with the attack - you are on the right track.


- Patience and Consistency.
Let me explain the title of this section..
Do not get impatient and change tactics and/or formation after one, two or even three bad matches, same applies to players.
Like real life it takes time for it to gel, also like real life it takes players time to adapt to the players around them, their role and tactics to become effective.
One example I can name is when I bought Jozy Altidore in FM14. He was transfer-listed by Sunderland, I wondered why, so I checked his history and the season before he was given about two games to prove himself, scored nothing, assisted nothing, and was shoved in the u21s. I bought him for something on the lines of 1.5-2.5 million, for me - a bargain. The first 8-10 matches I played him in he must have "accidentally" notched one goal, with an average of roughly 6.2, if that.
I subbed him off about 60-70 minutes in, so he got plenty of time under his belt (important to do so, but you don't want to sacrifice wins for the sake of one player), started him in every cup game and played for 90 minutes also.
After those 8-10 matches he became one of my most prolific strikers I have ever had. After about two seasons with him as my main striker, he must have banged in about 60 goals in 70 something matches - and that's not including assists.


- Keep your Eye on the Transfer-List
One of my favourite places to go in the game.
More often than not you find absolute gems in the transfer-list. Yes, they may be having a hard time, even for more than a year. Horrible form, aging, no match fitness at all. If you know how to give a player match time without sacrificing wins and you don't have money to splash out on the talents like Neymar, always keep an eye on the transfer-list.
An example here, or should I say two examples, I bought Stevan Jovetic for 3.5 million at 26 years old from Man City and Christian Eriksen at 23 for about 4 million. Even if you don't want to keep them forever - the amount of money you get just from the investment can be hugely productive and helpful for your club. To put it simply, the both ended up amazing players (as you can imagine being who they are) and they sold for A LOT. After two seasons of using them I sold Jovetic for a handsome 35 million and Eriksen for 30 million.
Positives: Cheap, long-term I made 57.5million PROFIT, incredible players when I had them
Negatives: A few goals may be sacrificed when first getting them back into form.


(An honourable mention here - keep an eye on the free agents list too. Make the search parameters to be within 6 months, you can find the best freebies people have to offer, similar to how Bayern signed Lewandowski for free from Dortmund in real life)

There are of course other things you can do to be successful, but as I mentioned - these are the pillars, the foundations of success.
Lay these as your primary paving slabs and you will walk your way into the halls of fame.