Always give them a sniff first, and if there is no funny smell i proceed with oral. 

Is it me or do other punters like to give ladies oral?  My introduction was as a 20yo the then G/F didn’t want fellow students to know she was having sex, so we made a plan.  I crept into her bed room at 4.30 am, I suspect she had masturbated, perhaps had a wee since showering, he unshaven pussy was rich in scents and juices, I soon learnt to give her wonderful oral and she reciprocated!

Some ladies don’t receive, I tend to avoid them, then there are some who have fresh knickers on that smell of fabric conditioner! When approaching there pussy, I always wonder: has she lubed herself, has a partner of perhaps another punter BB her recently, then I go for it and enjoy myself forgetting these worries as my tounger enters her!