Soya milk contains nearly as much protein as dairy milk, and this makes it ideal for baking where structure is important. It has a mild nutty flavour which works well in both sweet and savoury dishes. It curdles with acid, which can be useful in certain recipes that require buttermilk, however this does mean it tends to curdle in coffee, unless you get a barista version!
If you are following the low-FODMAP diet, it is suggested to go for milk made from soya-protein rather than soya-beans.
Almond milk is often chosen for its subtle nutty flavour. It works well in smoothies, cereal, or as a base in soups and sauces. However it is not great for baking due to its low protein and fat content. As per soya milk, it can split in coffee unless it's a barista-specific version. Obviously if you have a nut allergy this will be a no go.
Rice milk is mild and sweet. It has a light, watery texture and neutral taste. A safe option for people with soy, nut, or gluten allergies. It is not good for frothing or baking as it is low in protein and fat, so it's not ideal for recipes requiring structure or richness. It does work well in cereal, smoothies, or light sauces.
Oat milk is naturally sweet and has a creamy texture. It is great for coffee as it foams well and blends smoothly, making it a popular choice for lattes and cappuccinos. Again oat milk is not as good as soya milk for baking, as it is low in protein. Oat milk is often seen as the most environmentally friendly option. Oats are not gluten-free so this could rule it out for some people.
Coconut milk is creamy and rich with a high fat content. The canned version is great for desserts, curries, and creamy sauces. As well as the canned version you can buy a thinner version in a carton. The flavour is strong, so it works best in recipes where a coconut taste is desired! For coffee it doesn't foam well, and the flavour may be too strong depending on your preference (I quite like it in a chai latte). It's not so good for baking due to a low protein content.