For many small businesses that usually opt for LLC structures, I've heard anecdotally that Nevada and Florida are good states with LLC-friendly laws - as opposed to Delaware and its C-Corp-friendly laws.
Disclaimer: I am not a lawyer, so take this with a grain of salt. I would recommend consulting a lawyer to get a more definitive answer.
Delaware isn't particularly useful for early stage LLCs, but bear in mind that your home state may be a bear to file in. Some states, like NY, require you to run ads in a newspaper.
Plus if you want to do business in NY you may be forced to file as a foreign LLC, which also requires you to do the newspaper ads.
Filing in a state that you aren't yet doing business has no benefit and could actually hurt you.
By registering in a state you are consenting to being sued there. Why would you register a Delaware (or elsewhere) LLC when you are in California. Bad idea.
Second, if you don't register in your home state it could be found that you aren't operating an LLC at all. Say hello to personal liability for your debts.
Register in your home state, and as you expand to operations/contacts in other jurisdictions, register there.
There are three states where LLCs are commonly formed: Delaware, Nevada, and Florida. VCs, accountants, and lawyers are all familiar with the laws in these states, which are well-established and friendly to small businesses. This means that any disputes are likely to be resolved faster and cheaper in court should they ever arise.
The only downside is that you might have to register the out of state LLC in your state, and depending on the state, you may have to pay some extra taxes. But the benefit of filing a well-known LLC is far worth the hassle.