Here is a whole bunch of past posts on dressings.
If you enjoy a classic Mediterranean vinaigrette (3:1 oil:balsamic vinegar, salt, and pepper), you could try reducing the oil and salt until eventually you only splash balsamico and crushed black pepper over your greens. You could use any acidic or sweet juice instead of vinegar.
If you like curry and sweet/spicy flavors, one of my favorite things is a sort of mango-chutney inspired sauce, it's delicious and you can mess around with the ratios depending on if you like more or less spice or sweet, how thin you want it etc:
Ripe mango or tamarind (or both!)
Lemon, lime or orange juice
Water or your favorite plant milk to thin (A little soy milk makes it really creamy)
Your favorite curry powder or spice blend (kerala curry, generic south asian curry powders, even garam masala or something similar)
Dates- no point if you use tamarind unless you want something really sweet. Even if using mango, not needed, though it can replace soymilk in making the dressing creamy.
Chilis- if you want extra spice.
Works great as a sauce on rice/corn/potatoes too.
Another thing I really like is massaged kale- just get a heap of kale in a big bowl, dump on some lemon juice and maple syrup (spices, ginger, garlic if you're feeling fancy) and then crunch it up with your hands, massage it around, beat it into submission basically- makes it easier to chew and appetizing raw and is really tasty.