Not sure if you are still interested, but here goes anyway seeing as FIFA 15 is just round the corner.
It takes a long time to build up a good squad, and you can get really good squads by just having patience. My advice is buy gold premier league players for 300 coins and make a reserve team full of them. The reserve team can be used for offline matches, saving contracts and regaining fitness for first team. Once a reserve team player has run out of contracts, discard the player and you will get a minimum of 300 coins, +4 coins for every raiting over 75 for every non shiny and +8 coins for every raiting over 75 for every shiny. This way, you can win offline and are not wasting money on contract cards and fitness cards. Then just buy a replacement 300 gold player.
Equally, buy gold prem playes for 300 coins and sell them for minimum 350 on the market, this works especially well at the start of ultimate team. Small gains, but all help.