I made some with Coconut Oil recently --- you just have to serve it warm. Once you head down the warm dressing path, you start thinking about bacon dressing and stuff like. Ghee is another idea that could work. I don't think it is so hard. The only issue will be that in the fridge it will be solid --- you have to remember to bring it out and warm it before serving.
I don't have a standard recipe I just throw some melted oil, vinegar or lemon juice, spices, S&P.
Recently someone gave me a spice mix that was meant for olive oil dipping sauce for bread, I have been using that to make salad dressing since I received the gift. It is basically garlic and italian seasoning, salt and pepper.
With coconut oil I like to use asian flavors: ginger, fish sauce (or wheat-free soy), rice vinegar, and melted coconut oil.