OK, my experiences:
They are pretty time consuming to tune, you should use a passenger to monitor AF ratios, knock and map points if tuning on the road.
First see if you are running closed loop or not, in ETC, under FUNCTION SELECT. It can be enabled and disabled in the same way knock warning is.
Do you have aftermarket injectors? If so you need to make injector correction on the 'injector' menu in settings. If you are using an adjustable FPR, you will need to determine the flow with the adjusted fuel pressure to make the injector correction values.
This is what the power fc uses to determine how much fuel to use when running closed loop - and can make a massive difference to your fuel economy.
If these are already OK, ie fuel correction (if applicable) and closed loop were already correct, then you may need to remap. BUT, if you needed to make changes to them, this may fix the problem, and it would be worth driving for a while to see how economy is.
Fuel economy under boost is something that probably wont make a huge difference to economy unless you are boosting 100% of the time - most fuel economy gains seems to come from sorting the maps for just driving in traffic or cruising.
To check the maps for part throttle:
Firstly, switch off the closed loop function (you will need to switch it on again later)
Maintain 60kph in 4th, check the AF ratios and which map point you are using (via the map trace). In SETTINGS, go to INJ then to the appropriate map point (as found from the map trace) - from here you can make the necessary adjustments. You should aim for A/F ratios of 14.5, as this is stoich.
Do the same for other speeds that you normally drive at, 80, 100 etc and in the gears you normally drive at those speeds at.
MAKE SURE, you monitor knock levels. If the knock starts to rise (it should be very low, 1-3 at this stage, you are just cruising), back off timing by 1 degree increments, 1 degree makes a fair difference, then check it again. This is done in the IGN menu.
That is a basic run down on cruise economy tuning.
For power, AF ratios should be alot lower - if you are tuning yourself, do a run at WOT (keep a close eye on knock) - check the map trace, then adjust fuel for those cells until it is stable - I would suggest trying around 11:1. Do runs from 2-3000rpm, then adjust until they are ok, then do 3-4000rpm, etc. Use 4th gear, as this is where most load is on the car. After you have sorted the AF ratios, then its time to attack the timing. Add timing until knock levels start to rise once again, try and keep knock under 10, when you get to 10, pull one degree, check knock is down, then repeat the process for the next cell. You will have a rough idea where the timing needs to be from the previous point.
As mentioned this is a lengthy process - it can take many hours.
******DISCLAIMER********
IF YOU DAMAGE YOUR ENGINE, I ACCEPT NO RESPONSIBILITY IN ANY WAY. I RECOMMEND YOU TAKE YOUR CAR TO AN APPROPRIATELY EXPERIENCED VEHICLE TUNER AND GET THE CAR TUNED ON A DYNO.