What I did was no matter what, I upgraded my arena. Now I have a really huge arena, maybe a bit too big, lol. But I get good money, and I lowered prices a bit to try and pack the arena, now I get 21k fans coming to watch games. But I went through relegation twice, while also changing out players during the time period, even changed trainers a couple of times till I could get one that was great, and still bring in a lot of money. Now I will save up and see if I can get an exceptional talent. Relegating to Div. 5 really helps if you're winning down there and have a nice stadium size.
Now the reason I say upgrade stadium before all else is this....if you get a bunch of solid players, but they have you middling in the league, or you are in a league who has great players, then you aren't really going anywhere, and you're not making as much money as you could because you are spending on your players contracts, and still not winning much. Go arena. I went arena and went in the hole plenty of times because I would put all of my money into expanding. Expand when you have a good chunk of money. It's good to win leagues and everything, but don't worry about winning so much right now. Worry about getting the money to flow in. If you are not filling your arena, lower the prices and when that price drop date hits, it could really help you. And, as Sparta said, there is an arena management tool now that helps, which I didn't find out about till a few weeks ago, lol. Anyway, good luck. Now if I can save up money to the millions, I can truly have an exceptional player.
And, If you are desperate for money, have a very good player that could get you some good cash, and he's a bit older, (I sold my early thirties players, even late 20's and picked up cheaper, solid replacements, though not as good), sell them, get some cash, up that arena.