Do you need to track inventory or change pricing for a product's variations for size, color, metal type, etc? If yes, then Product Variations is the best method. Each variation will have it's own product listing with controls on pricing, inventory, multiple-image uploads, and more.
If you are creating products with variants of the same price and you do not need inventory tracking, then Product Options is the best tool. By using Options, each "variant" of the product does not create separate products in your All Products list and will reduce clutter. This can be used for chain lengths, fabric colors, custom names, etc.
See this video on an example Product with Options: