Summarize:

As noted in the intro, there are hundreds of ways to make a BLT. This variation adds a little west coast flair to the standard BLT by adding some of the key ingredients in a California club sandwich. To start, you'll want to build a BLT as directed above until the point just before you'd normally be finished. In other words, cook some bacon, then spread a little mustard and mayonnaise on your bread, and finally add tomato, lettuce, and your cooked bacon to your sandwich. From here, we'll be adding a few extra touches to make our sandwich unique. For a true west coast classic, you may want to consider using sourdough, San Francisco's signature bread. Peel and cut a ripe Hass avocado into several thick french-fry sized slices. Lay these slices down above your final layer of bacon. The avocado gives the sandwich a creamy, satisfying quality not present in an ordinary BLT. The smooth texture of the avocado contrasts especially well with crunchy toast. Avocados are best when they're ripe. Ripe Hass avocados (the most common variety on the west coast) have dark green-to-black skin and a firm, yet yielding texture. The fruit should feel somewhat weighty and should have no obviously flattened or "smooshed" patches. If you're unsure whether an avocado is ripe, check under the brown stem remnant at the bottom of the avocado. If the skin underneath is bright yellow-green, you've picked a ripe avocado. If it's brown, your avocado may be bruised or overripe. After adding your avocado, you may want to squeeze a thin slice of lemon over your sandwich to produce a few drops of lemon juice. If you do so, be conservative — you want just a hint of lemony zest, not a BLT that makes you pucker. If done correctly, the BLT will have a slight tangy flavor which, for some, is absolutely mouthwatering when paired with the meatiness of the bacon and the smoothness of the avocado. Congratulations! Your California BLT is ready to eat. If you desire, you can add another layer of ingredients and an additional piece of bread to create a double-decker. If you're looking for a truly Californian experience, you may want to opt for this — California clubs, the state's signature sandwich, are customarily served as double-deckers.
Assemble a classic BLT, minus the final piece of bread. Add a few avocado slices. Optionally, add a spritz of lemon juice. Add your final piece of bread.