Write the plan first, get buy-in, then build
Before I build a tool that other people will use, I write a short plain plan and show it to whoever's affected first. Not a technical document, just a few sentences on what it does and why.
Skipping this step means you might build something nobody actually wanted, or something that conflicts with a habit your team already relies on. A short plan shared ahead of time catches those problems while they're still cheap to fix, in a sentence, instead of expensive to fix, after a finished tool needs to be reworked. It also means the people using the tool feel some ownership over it, since they helped shape it early.
Try this today: write a short plain plan for your next shared tool and show it to one person who'll actually use it before you build anything.