UUA shouldn't help get you more TP.

Two return trips to Istanbul, or one return trip to Jersey/Scotland then on to Istanbul, might work.

One return to IST (one leg can be in economy) + one GVA-LHR-MCT-LHR in WTP seems like a good bet if you want to travel. Just make sure that the economy LHR-IST is in at least an N bucket, and pay cash for your GVA positioning flight. (Or, if you get a POUG to GVA, just to a domestic club return).

OSL-HEL-AGP sounds much more pleasant than it is (check the timings) but it does earn you 360 TP for under £600.