After searching multiple sources on how to add attributes to Virtuemart 2 and finding a bit here and a bit there and then just messing around to get it to work, I've decided to type it up for the benefit of humanity. Here goes. May you have a simpler time than I did.

1. Login to backend administration to joomla.
2. Hover over Components and click on Virtuemart
3. From the Products Menu, click on “Custom Fields”
4. Click on the “New” icon at the top right (the big orange circle with the + in it)
5. In the “Custom Field Type:” dropdown, select “Cart Variant
6. Type the Title as you want it to appear on the front end of your store. Example: Size or Colour.
7. Make sure it is published.
8. Do not select a parent
9. Make sure the “Cart Attribute” is set to “Yes”
10. Leave Description blank
11. In the “Default” field, type your attributes separated by a semi-colon.
12. Example for Size: XXL;XL;L;M;S
13. Example for Color: Black;White;Red;Blue
14. Leave the “Admin only” radio button set to “No”
15. Have the “Is a list?” radio button set to “Yes”
16. Have the “Hidden” radio button set to “No”
17. Save & Close

Next, add it to the product:

1. Click “Products” from the Product Menu
2. Click the name of the desired product to add the attribute to
3. Click the “Custom Fields” tab at the far right of the product tabs
4. Click the dropdown under “Custom Field Type”
5. The title of the custom fields you just created should appear in the drop down
6. For each of the items you added to the “Default” field in the custom field, click the desired custom field title that many times. So, if you have 3 sizes, small, medium and large, you click the dropdown under the Custom Field Type 3 times.
7. When you do so, 3 new lines will appear under the Custom Field Type area showing the title, a value (with a dropdown), price field, type, cart attribute and delete.
8. In each of the new lines that were created for your title, select the “Value” desired to show up in the store. So, if you had 3 sizes, you would select “Small” from one drop down, “Medium” from the next drop down and “Large” from the 3rd dropdown.
9. To show a different price for different attributes, enter that price into the “Price” field. To have no price show at all, make sure the field is blank. Remove the “0.”
10. Click Save & Close.
11. Check it from the front end.