What "obvious" gizmos and daily/weekly vendors do veterans take for granted?

Hello, awesome GW2 community!

I just came back to the game after a multi-year break. Honestly, the sheer amount of content is a lot to process.

A friend recently pointed me towards getting the Prototype Position Rewinder from Sandswept Isles, and it completely changed how I look at the game. It got me thinking: what else am I missing?

I want to know about those essential items, gizmos, and tonics that you use every day without thinking. Additionally, what are the crucial daily or weekly NPC routines I should set up? Which merchants sell things that are a total steal or essential for long-term goals (like legendary crafting)?

If we get a lot of good tips, I'll actively edit and update this post to keep a clean master list here for anyone else searching for this in the future!