Shopify Changes

I am looking for a Shopify expert who can help me make design and layout changes to my store. I have a rough idea of how I want the store to look, but I am open to suggestions. It is important that these changes are mobile responsive.

Ideal skills and experience:
- Proficiency in Shopify and its customization options
- Experience in making design and layout changes to Shopify stores
- Knowledge of mobile responsive design principles