It should be student88 anyway... I think you are an easy driver... Check your VistAir - a new manual was issued today covering this very subject.
If every A319 in easyJet did a flap 3 v flap full landing it would result in a saving of £3.0m, for the A320 its £550k
The biggest saving that we as crew can make, is not carrying fuel above OFP when there is no justification for doing so, I understand that we will soon be having an update to our OFP's showing the percentage of flights that operated on that sector without burning more than OFP fuel. (98-99% of flights)
But yeah, unless unable for operational reasons you should be doing a F3 landing, and it is the normal landing configuration to be used.