I have been trying a few session beer recipes of late and I have found, as already stated, replacing base malt with malts such as Munich/Vienna with crystal malts will give you that malty backbone that you need when decreasing the ABV.
My current Mid APA which I am really happy with at 3.8% (Roughly 50% base Pale ale malt, 30% Munich 1 and the rest Wheat and Crystal) is hopped from 15 mins to go in the boil to flameout and dry hop to give me both my flavour and desired bitterness really adds balanced hoppy goodness. I used Saf Ale US05 and mashed at 68c.
This hopping schedule makes a huge difference IMO (as well as the mash temp etc) to the flavour you get and need in a lower ABV beer.
I have to say thanks to Dr Smurto for this tip!