Hubs are tough, especially the forteresse variety, and probably expensive. Cheapest/least painful would be CDG-LON-CDG in classe affaires (~€320) for 30 XP. The ideal seems to be to start from some origin that only one of the 2 or 3 (or 4) Euro ST airlines fly to, and go on to a destination that only 1 of the remainders flies to, so you have to route origin-hub1-hub2-destination and back. Not only that bu the O&D pair must be preferably served by a competitor to keep fares low. 3 x 5 XP each way (painful perhaps, I'll admit).

Once you pass 100 XP, you'll get FB Silver and any surplus will rollover for another year either towards requal or Gold (another 180 XP).