There are several different ways that products can be organized in a catalog. The best one depends on the type and number of products and the catalog's overall branding identity.
For example, clothing items can be organized by type (tops, bottoms, sweaters, dresses, etc.), season (fall items, summer items, etc.), collections, or even fabrics/materials (leather items, knitwear, etc.).
Other products might lend themselves more to alphabetical listings, for example, if the products are ordered via an SKU, product code, or part number. This is also practical if there is a large number of items that you can list in chart format without needing pictures of each item. The latter tends to be used ...