In a bowl, using a fork, stir together refried beans with 2 Tbsp water (or more to reach desired consistency. You don't want them to be runny but not so thick they'll break the chips either). Mix in taco seasoning.
Peel and core avocados and mash with lime juice to reach desired texture, while seasoning with salt and pepper to taste.
To assemble:
Add a heaping spoonful of the bean mixture to the bottom of cup (careful not to smear it along the edges or you'll mess up the look of the layers. It doesn't have to be perfect and you can wipe it of with a damp paper towel as needed) then spread into an even layer using the back of a spoon.
Add a heaping spoonful of the avocado mixture over bean layer and spread into an even layer, then follow with a layer of a spoonful of sour cream (spread) then a spoonful of salsa if using (spread).
Sprinkle with a layer of cheese, then finish by layering tomatoes, black olives and green onions. Store in refrigerator and serve with tortilla chips.
Notes
For the tacos seasoning: in a bowl combine 1 Tbsp chili powder, 1 tsp paprika, 1 tsp ground cumin, 1 tsp salt, 1/2 tsp pepper, 1/2 tsp onion powder, 1/4 tsp garlic powder, 1/8 tsp cayenne pepper. Use what is needed then store remainder in an airtight container for another use.