waist

Question
what type of swimming technique can I do to whittle my waist?

Answer
Kathie-
The best way to whittle your waist isn't with swimming, that's because since body fat floats, swimming isn't the best way to burn fat.
The best thing to do is to start with crunches(half sit-ups), side sit-ups and leg lift type of exercises.  Swimming is great for the cardiovascular aspect of fitness though.  
Hope this helps,
George