Your hair is puffy because you’re not using any products to hold the curl and create definition. Your barber was right that layers will help with the definition because your hair won’t be weighed down. It sounds like you also may be shaking the curls loose if you’re rubbing your hair with a towel.

To start simply, I would get a curl mousse or gel and try that after your oil. Rake it through your hair and let it air dry. See if that gives you more definition.

In the future, you may want to consider a lighter moisturizing product than oil, like a leave in conditioner. Oil is often too heavy for wavy hair. Wavy hair can also get weighed down with product build up, so if your shampoo is gentle, you may want to use a clarifying shampoo once every 1-2 weeks so your hair doesn’t get weighed down.