I think that the BCBG brand does it brilliantly.
Most fashion brands change frequently to keep up with trends. However, BCBG also has a history of continuing popular pieces from season to season in new colors, materials and patterns. So, if you find a pant that you love, a purse that you adore or a dress that fits you just right, there’s a good chance that you can find it again with a twist. And if you are at all a fashionista, you know how valuable it is to be able to access pieces that fit your style and your body just right.
For example, their signature envelope clutch has been around for years, but each season, it gets a new slate of colors and finishes.
Think about how you can implement this strategy in your business. Can you keep a core of what you do the same, but offer some variations from time to time to incent new purchases? This gives your loyal customers a reason to stay with you but to buy again, and also gives you an opportunity to attract new customers.