Start by making sure all ingredients are chopped. For each salad, per person, you'll want an even amount of ingredients. I eyeball a similar amount of tomatoes to bacon and avocado, with a smaller amount of red onions and feta.
To assemble salad, mix together spinach and green leaf lettuce. Place into the bottom of a salad bowl.
Top with chopped bacon, tomatoes, feta, and red onion. If you're waiting to serve the salad later or to bring to an event, wait to put avocado and dressing on top until just before serving. Otherwise, top with avocado.
Just before serving, slather salad with creamy herb dressing and toss well.