[michaelflux]

Depends on the target demographic.

If the product needs to be something a bit more serious, e.g. fintech product, then take an existing term in the industry or something that clearly relates to it, and put some small spin on it, and a .co and you're ready to go.

If the people I'm targeting are younger, trendier etc, then take any loosely related word, check Google Translate to see if there are any cool sounding translations of it, find something that is short and catch, add a .io and you're good to go. :-)