do all the night hours that you can and do long flights into europe remember the customs man will give you money to go abrord (about £50 for a PA28 with full tanks) the landing fees are cheaper in france as is the fuel ,also use the channel islands when you can for very cheap fuel.
If you can do a few air rallys it will sharpen up you navigation skills for the GFT and its good fun ,i can recomend the guernsey air rally as a good place to start it is held in mid september and i dont think you can beat it for a weekend of cheap flying fun .
The reason you need night hours is for the issue of the ATPL most people seem to be short of night hours come issue time so with a little forward planning you can avoid this pitfall.