Airtable Jewellery Database Build

I have started this Airtable but need help finishing it

I need a well-structured Airtable base that keeps my entire jewellery business in one place. The base should include three interconnected tables—Products, Customers and Sales—so I can see stock levels, understand who is buying what and quickly pull sales reports.

Products
• Each record represents a single SKU and is categorised by type (rings, necklaces, earrings, bracelets, etc.).
• Core fields: product name, type, material, collection, cost, retail price, quantity on hand and photo attachment.

Customers
• Store contact details (name, email, phone, shipping address).
• Track purchase history through linked Sales records and allow room for notes on preferences such as size or metal choice.

Sales
• Capture every transaction with date, order number, items sold (linked to Products) and revenue.
• The link back to Customers must automatically build a purchase history roll-up so I can see lifetime value at a glance.

I’d like formulas for margin calculations, a dashboard view that highlights top-selling product types and simple filters for seasons or promotions. If you can add an automation that emails me when stock for a product type drops below a threshold, that’s a bonus.

Please deliver the Airtable base (shared with my account) plus a short Loom walkthrough so I understand the structure and any automations you’ve added.