Say "no" much earlier
Across every scale, from the individual up through multinational organizations, there will always be more ideas for things to do than time to do them.
Every time you say “no” to such a project or task, the further along the path you’ve taken it to completion, the more time and effort is effectively discarded. We find silver linings in lessons learned and context gained, but we don’t deliver what we’d initially intended to.
Knowing both these things, it makes sense to check in early on in the planning and shaping stages of work to find clear indicators that it’s something unlikely to be finished, accomplished, or otherwise done. The sooner you discover that a “no” will be the outcome, the more you can focus on your “yes”.