I have been playing sins off and on for a few months.  I have played several games and usually my fleets (TEC) usually end up looking like this:
Early Game - Kol Battleship, 15-20 light frigates, 5-10 LRM frigate, 5 Support carriers (cruisers with squadrons)
Mid Game - Kol Battleship, 20 - 30 light frigates, 10-15 LRM frigates, 5 Support carriers, 10 Flak frigates, 2 Command  Cruisers, 2 Repair Cruisers     - a seperate fleet(s) of 10 siege frigates
Late Game - Kol Battleship, 30 - 40 light frigates, 15-20 LRM frigates, 5 - 10 Support carriers, 10 - 15 Flak frigates, 2 Command Cruisers, 2 Repair cruisers, 10 Heavy Cruisers   - a seperate fleet(s) of 10-20 siege frigates
The fleets above are my main fleets, I'll usually also have (depending on the size of the game) a few other slightly smaller fleets with either a Kol Battleship, Carrier, or a Dreadnought.  Usually only one cap ship per fleet but sometimes I vary it.  Anyone else have similar strategies, improvement ideas?