Conditioners certainly fall into this category. You may think the answer to “How to use conditioner” is fairly obvious (uh, don’t you just put it in after your shampoo? I can practically hear the eye roll!), but in practice, using this item comes with a lot of alternative practices. And it’s worth experimenting with new ways to use it to see what works best for your hair type. Think of it like washing your face: You need to top that fresh skin with a hydrator to keep water in the skin, as well as enhance skin barrier function. And while your hair isn’t a direct comparison to your skin (your strands aren’t made of living cells like your skin is, thus it doesn’t have true regenerative properties), it does hold true that your hair needs moisture to look and feel its best. Without it, hair becomes brittle and breaks easier. If you’re using conditioner this way, do make sure that you’ve wrung out the excess water from your hair before applying it so the nutrients in the product can penetrate the shaft easier. With co-washing, you’ll want to occasionally skip the shampoo and sub in a co-washing conditioner (it’s formulated to gently cleanse the scalp while hydrating the ends). As for how often you do this, it’s up to you. “I highly recommend that clients become in tune with their hair. If the hair begins to feel oily, or oversaturated—alternate frequently with a sulfate-free shampoo,” Danielle Malary, owner of Lumiere Vive Salon, told us. “The routine should be specific to the client’s hair and needs.” One method for rinsing out conditioner while leaving a bit in is by pooling the water in your palms as you rinse the product out. As you are doing this, you continuously scrunch the conditioner-water cocktail back into the strands. This helps you have more control over the amount of product left and in what areas. To learn more about this rinse-out method, check out our how-to here. With these, you’ll want to apply them post-shampoo, like a regular conditioner, except you’ll want to make sure you give it ample time to set. (Most hairstylists recommend a range of 10 to 30 minutes.) They should ideally also be applied with heat. In a pinch, it’s totally fine to stay in the shower and let the steam do its thing (use the time to shave or exfoliate!). But if you want to really amp up the efficacy, wrap your hair in a shower cap, turn off the water, exit the shower, and use a blow dryer set on low speed and warm. After, you’ll rinse out as usual. As for application, you’ll want to use it post-shower while your hair is still wet. This way, the conditioning oils and emollients will help trap in the water and seal down the strands’ cuticle (which is naturally raised from being exposed to water). According to hairstylist and founder of Hair Rules Anthony Dickey, if you want more volume, you’ll want to towel dry first; if your concern is more about curl definition and ridding hair of frizz, apply it when hair is sopping wet (keep the leave-in in the shower, even, to remember to do this).