Usually, there are customers who respond very well to new collection/ product announcements and convert from messages saying "new", "trendy", "be the first to..." and so on. They don't wait for a sale and pay full price, which is great for your margins and you should be stimulating orders from them every time you have a new item.
How to find those people?
In the Customer database tab, filter customers by Mail campaign that announced new products. From the options there, choose people who"ordered".
OR, use a filter for the product categories they ordered. This should be your NEW IN or similar category.
You can now apply a tag to the whole list and easily send them all exclusive early-bird offers for every new product or collection you have.
That'd give you traction as soon as you make a new launch and will kick off early sales and reviews. It's good to have a stable group of early adopters eager to get the product.
How to stimulate orders by those early buyers?
between launches, keep them engaged with trend guides and sneak peaks into what new's coming from your brand
invite them to shop before everybody else
make them part of the process - naming, packaging, etc.
make a discount for word-of-mouth and social shares