You just need a stick blender.
Put 2 egg yolks (preferably organic) in a wide mouth pint jar.
Add 1/2 teaspoon salt,
1 Tablespoon apple cider vinegar,
1 Tablespoon lemon juice,
1/8 teaspoon each onion powder and dry mustard (adjust to your taste).
Add 1 cup regular olive oil and allow everything to come to room temperature (very important).
Then put stick blender in down to the bottom and turn on and count to 10 before you bring it up slowly on one side of jar.
The oil will emulsify as you gently move the blender up and down. It shouldn't take more than a few seconds.
Scrape off blender and put a cap on jar and refrigerate. We've been doing this for years and love it. (you might want less mustard)