Names get expensive at a specific point: the moment something physical or contractual exists with the name on it. Before that, changing your mind costs an afternoon. After it, it costs money and explanation.
This is the list worth working through in that gap.
1. The full availability sweep, in one go
Domain and every handle, at the same time, on the exact spelling you intend to use. Not the version with a capital letter, not the version with the word order you were considering — the one going on the packaging.
Do it in one sitting because availability moves. A handle you checked three weeks ago is a handle you have not checked.
2. Claim everything, immediately
Not later. Handles cost nothing and take a minute each. Register the domain the same day. The gap between deciding on a name and holding it is the only window in which you can lose it, so make the window short.
Take the handle on platforms you have no plans for. You are not committing to using them; you are preventing someone else from being you there.
3. Say it out loud to someone who hasn't seen it
Then ask them to write it down. This catches, in about fifteen seconds, most of what goes wrong with names: ambiguous spelling, an unclear separator, a homophone you didn't notice, and a word that sounds like a different word entirely on a phone line.
If they ask a clarifying question before writing, the name will generate that question forever.
4. Read it with the spaces removed
Every handle is the name with the spaces taken out. Read it that way, slowly, and look for a word you didn't intend. This has ended real brands and it is always obvious in hindsight.
Have someone else do it too. You know what it is meant to say, which makes you the worst person to spot what it does say.
5. Search it
Plainly, in a search engine, in a private window. You are looking for two things: whether something enormous already owns this word, and whether the results are so crowded you will never surface. Neither is disqualifying. Both are worth knowing before you commit.
6. Check the trademark position properly
This site reports technical availability. It does not tell you whether someone holds rights in a name, because that is not visible from a handle check and we will not imply otherwise.
If real money is about to be spent, a trademark search in the classes and territories you will trade in is the thing that matters, and it is work for someone qualified. The national trademark registers are searchable for free if you want a first look, but a clean-looking search is not clearance.
7. Buy the obvious defensive variants
The plural, the singular, the common misspelling, and the .com if you have taken something else. Redirect them all to the real one. This is cheap now and awkward later, when someone else has noticed.
8. Then print
Once the set is held and the name survives being said out loud, the expensive decisions are safe to make. Everything above takes an hour or two. A rename after launch takes considerably longer, and the guide on doing one exists because it happens often enough to need writing down.