What gadget do I need to add soft waves to my hair?

[Savagebeauty]

I have thick poker straight hair which is a similar length to the pic.
What can I use to make it more it more interesting??

[Ginmakesmecry]

m.asos.com/mt/www.asos.com/Babyliss/BaByliss-Boutique-Soft-Waves/Prod/pgeproduct.aspx?iid=5640979&istCompanyId=6f061ed0-7427-4b6c-bb90-987c0bd08468&istItemId=llqmiptmm&istBid=tztx&affid=14179&channelref=product+search&utm_source=google&utm_medium=ppc&utm_term=41477300408&utm_content=&utm_campaign=&cvosrc=ppc.google.41477300408&network=g&mobile=1&search=1&content=&creative=53983301781&ptid=41477300408&adposition=1o1&r=2&mk=ab&gclid=CPyV9qLM6cwCFagy0wodswoK4w&un_jtt_application_platform=newPlp&un_jtt_redirect. I have this and it's fantastic at giving the soft beach wave look.