I am always playing lower reputation clubs.
I have never managed big clubs; I have been job refused proposal from bigger clubs.
First rule: Keep tight wage budget. This is crucial.
Second: I am always invest money at training and youth coach & facilities.
Third: If I have a wonderkid (age 19 - 20); I am always selling to bigger clubs. This is going being hard emotional, but it's business (ok, it's a game). What about 20 mil euros offer for a wonderkid from a country which has 2 mil euros TV deal? That's an equal to a 10 year TV contract. Not bad.
Fourth: If you play an EU club, always try to win leagues. Champions Leagues qualification (money) helps to maintain finances under control.
Fifth: Since you have perfect balance (and good amount) at finance, it's nice to invest at wonderkids from other clubs. That;s require scouting dept. Invest at the best.
Hope that helps