As you might already know, there are simple ways to make sure your wardrobe doesn’t contribute to the mass amounts of pollution created by the fashion industry. For instance, you can avoid fast fashion and buy second-hand clothes. You can also buy durable clothes that are sure to last. These steps to cleaning up your wardrobe are rather obvious, but there are few less commonly known tricks that can help you develop a more sustainable wardrobe. Here are four of them.

First, do the ’30 wears’ test. When faced with a potential new outfit, ask yourself if you’d wear it 30 times or more. If the answer is no, walk away. This will eliminate many of those special occasion outfits and shoes that have few opportunities to be re-worn and will push you toward more versatile, practical pieces.

Second tip: invest in trans-seasonal clothes. Clothes that can cross-seasonal boundaries are the most useful investment. Often this means simpler pieces, like jeans, tees, blazers, and classic dresses. Consider the climate when making decisions. If you live a cool, cloudy climate, don’t splurge on summery dresses that will fail the 30 wears test on an average year; buy what you know you’ll wear and whatever can be layered for more seasonally-appropriate dressing.

Third, have a working list of go-to brands. Assemble a list of go-to retailers (online or in store) where you can source key items; add to it as you discover new ones. By being more deliberate with your purchases, you can support brands that serve the environment rather than destroy it.

Lastly, adjust how you spend your money. Don’t think of shopping as a chance to splurge on something frivolous. Instead, see it as an investment in a staple piece that’s going to be worn and re-worn. In the end, you’ll save money on more expensive, sturdy jeans rather than buying several pairs over the years.