You can simply go to Ali Orders > Order Settings > There will be a section called Check-out Note to Supplier on AliExpress.
You can simply write a note there for your suppliers about your order, describe it in detail to be correctly chosen.
Some templates for your reference:
We are dropshipping! Please, don't include any invoices or promo materials into the package.
Products are fragile, please be careful
Please wrap the product nicely and carefully.
Product should be shipped in working hours only.
Leave the products at the door mailbox.
The products is oversize, please help the customer to leave at the post office when it’s arrived.
Product should be exactly as description.
Remove the old information of your product and fill in the information of my products (e.g: price)
Finally, don't forget to click Save Settings button.