Most catalogue problems are decided in the first week and paid for long after. Settle these before the first import.
Product or variant. Variants suit versions of one item that share a description and differ by size, colour or material. Separate products suit items that need their own description, images, reviews or search presence. Shopify also limits how many options and variants a single product can carry, so very large ranges may need splitting anyway.
Option naming. Pick one name per option ("Size", "Colour") and one format for values ("Small" or "S", never both). Storefront filters group by these values, so inconsistency is visible to customers.
Manual or automated collections. Manual collections suit small curated edits. Automated collections pull products in by rules such as product type, tag, vendor or price, so new uploads land in the right place without anyone editing the collection. Most catalogues want mostly automated collections, with a few manual ones for campaigns.
Metafields for specs. Materials, dimensions, care instructions and compatibility belong in metafield definitions, not in tags or buried in descriptions. From there they can feed product-page blocks and storefront filters.
SKU and barcode conventions. A SKU format that encodes range, colour and size, such as TEE-BLK-M, speeds up stock counts and picking. Barcodes matter if you sell on marketplaces or advertise on Google Shopping.
An import template. The last deliverable should be a spreadsheet template with your columns, your conventions and one example row — so the next 500 products don't need a specialist.
