I was going to reclaim my most recent cashback amounts on
Topcashback and noticed a new payment option, via Tesco Clubcard points. You get a 5% bonus over and above the monetary value of your cashback. Here's some more info from the site:
So, £50 worth of cashback gives £52.50 of Clubcard vouchers, which you can turn into 12600 Avios (at current rate). Its a pretty good rate at just under 0.4p per Avios, much cheaper than buying from BA, and with regular conversion bonuses taking place, you could end up with even more.
Note that there is maximum limit of £50.
I typically redeem via Amazon vouchers (again, they give a 5% bonus here) but this is a nice new option.
If you don't use Topcashback, I can refer you