Thumbnail and Banner making for youtube video and chanel

I am looking for an experienced freelancer to create unique thumbnails and banners for my Youtube video and channel. A graphic design style is preferred, but I am open to all suggestions. I have a rough idea of the concept and theme I am looking for, but I am open to hearing different suggestions as well. The time frame for usage is open-ended, as I may use them just one-time or maybe but I may require these elements repeatedly. Ideally, the project will be completed quickly with high quality.