If you're going for strictly money, drop long haul and focus on a network that incorporates hubs that can serve airports from multiple hubs.
For example:
If you have hubs at ATL and ORD, adding JFK will allow you to serve most of, if not all your current airports without you having to rent more gates. If you add say, SFO, you may not be able to serve all of the same airports with your current fleet.
That hasn't always been my strategy, but if you really want to make money quickly, focus on having hubs with high pax traffic and that are near each other w/i 1,500 to 2,000 nm (depending on your fleet).
I'm not saying you can't do any long haul, but if you're doing TALT from ATL and ORD (I've had this come up), you normally need 4200 nm + range a/c and those are expense and you'll want to keep them under 3 years of age and then cycle in new a/c. Also general consensus is to keep the seats below 300, which the A300-600R or maybe the DC-8 may be your best bet for TALT flights. Not super familiar with L-1011s, but A306s have worked well for me.