I too use the inherent light meter system I was born with and have developed over the years.... although I am very fortunate in being able to bracket with alacrity. Simply, HP5+ is a very forgiving film but XP2 Super does indeed have a wider latitude. A low cost light meter as per Ian's suggestion would seem a very logical and practical step.
Signing off on a very , very rare f22 500th day in the North West of England, thank you for using and valuing ILFORD Photo products.
Simon. ILFORD Photo / HARMAN technology Limited :