Just me for side projects that generate a passive revenue. From what I can tell, the process seems fairly straight forward, but I ask because there are always caveats that people with experience learn from that I might be able to avoid.
You might investigate a "Series LLC" if you want separation of your multiple independent projects.
Series LLC is not available in all states and is fairly new but it allows for a master or an umbrella LLC and other LLCs which are separated from each other for liability purposes.
Each LLC has assets separate from the others, while the master LLC controls all the LLCs in the series. Each unit has its own owners (members) and is liable only for its own debts and obligations. A series LLC can be thought of as a corporation with several subsidiaries.
You can accomplish the same thing by creating a subsidiary LLC with its sole member as the Parent LLC. As a wholly owned subsidiary, it is a disregarded entity for tax purposes.
