Writing
For writing I have found a number of tools that help me create more in a sensible way. The main backbone of my process is Logseq a great way to organise and structure your notes and thinking. It is open-source using markdown files making your notes portable across various systems, you can just take them anywhere. And the community offers a dazzling array of plugins, from local LLMs, text-to-speech, Git version controll, to drawing utilities. If you like organising your thoughts and data you will love Obsidian. Oh and every page on this site is written on it.
I am dyslexic so writing has never been my strong suit. So I love my grammar support very very much. But Grammarly will use my writing to improve its products and lord knows what else. Luckily there are local alternatives. One that I have switched to recently is Harper. The code written in Rust provides fast, resource efficient gammar checking 100% locally. It comes with great integration with Obsidian, and if you write code VS Code and Language Server.