Hi Finema, so something like this - a 2D leaf in the top view:



Draw a line down the center of the leaf, and in a side view draw a bendy curve like this:



Select the leaf and run the Transform > Deform > Flow command, pick the center line as the base curve and the bendy curve as the target, that will make a result like this:


Repeat with some variations on the bendy curve, then rotate them:


- Michael