How do I do these type of curls/waves

[Overitx]

Every hair dresser I got to does my hair with nice waves. When I try either with a straightener or a wand they end up either really tight, too bouncy, too straight.

how do I do these type of curls? Is there a way to know?

I feel your pain - I can NEVER curl my hair with straighteners or a wand. However, I do the heatless curls with my dressing gown cord and it always looks amazing! Google it :)