Cheap and easy mini-TP run
In all the constant talk about not flying the fourth sector of an ex-EU, I wonder if we sometimes lose sight of something?
If you have no checked baggage, or your fourth sector is one which allows you to retrieve your bags before it (eg XXX-LHR/LCY-AMS) and store them or take them home, then some can use the fourth sector as part of a cheap mini-TP run. This seems to me to work particularly well if the fourth sector concludes at a place where you can easily turn around immediately and fly back to London on the same aircraft (eg AMS).
An AMS-LON can often be bought for cash for about £50 or so. Completing the fourth sector (LON-AMS) in CE and then returning to London for £50 means 50 TPs for £50. Alternatively, if AMS-LON is on an RFS ticket, it's 40 TPs for £17.50 + 4,500 Avios (and of course you'd earn back at least 750 by flying the fourth sector in CE and many of us would earn back 1,250).