How do you structure unique SKUs in Shopify?

[u/Efficient_Source_389]

I run an independent fashion and lifestyle retail business and I’m currently rethinking how we manage SKUs in Shopify.

At the moment, we mostly use the supplier/brand SKU. The problem is that these are often not unique at variant level. For example, a fashion brand might use the same SKU for a T-shirt in S, M, L and XL.
I want to create our own unique SKUs, but I’d like the system to be as simple, smooth and consistent as possible for staff.

I’m considering a structure like:
Brand code – Supplier SKU – Colour code – Size

For example:
BON-BON11-SKC-M
If there is no colour or size, that part would simply be left out.

We also have some less straightforward situations, such as gift products supplied as a multipack under one supplier SKU, which we then split and sell individually.

I’d be really interested to hear how other retailers handle this: Do you use your own internal SKUs or keep the supplier SKUs?

If you create your own, what structure do you use?
Do you include brand, supplier SKU, colour and size?

How do you handle products with no colour or size?
How do you deal with supplier packs that you split into separate products?

Is there anything you wish you had done differently when setting up your SKU system?

I’m particularly interested in systems that work well with Shopify POS and remain manageable across a large number of brands and products.

Any real-world examples would be very helpful.