Use a dusting of chalk on Latex seals when clean and dry after diving to prolong their life.  Latex has a memory and in its original it is a liquid, it tries to return to its original form and this is why they get sticky and gooey as they age, the chalk helps neutralize this reaction.  Some people use talc for this purpose but there are extra additives, perfumes etc  in talc that will react with Latex, and aid in the breakdown of the seal, French Chalk is totally natural.  Some people also like to use French chalk to help when fitting seals.