SZF - I mostly follow the same routine that you described. However, the AIP does not include all unlicensed aerodromes. Lacking an up-to-date AIP entry, I photocopy (scan) the appropriate leaf out of Pooley's/Lockyears.
One further observation, how many of us are flying around on a half mil that hasn't been updated in 9 months? For example, compare the old/new dimesions of the Brize Norton CTR.