Sea buckthorn has a strong, tart flavour that can be surprising if you're used to sweeter juices. A practical way to start is to pour a small amount (e.g., 30-50 ml) into a glass and mix it with still or sparkling water. You can adjust the ratio to find a balance you enjoy.
Another easy method is to add it to a smoothie with sweeter fruits like banana, mango, or a touch of honey or maple syrup. The other ingredients will mellow the sourness while letting you benefit from its nutrient profile. Over time, many people find they appreciate the tangy taste and may use less dilution. If you have a sensitive stomach or are sensitive to acidic foods, begin with an even smaller amount to see how it suits you.