There’s a similar discussion with a couple of solutions in this thread:
Yet, it is mainly about the question how to capture quick thoughts while you’re not working in obsidian (but still, some of the proposed solutions might be helpful in your case).
A rather comfortable solution within obsidian would be to use the “daily notes” plugin. Your current daily note can at any time quickly be opened via a simple shortcut. If you have any ideas, just open it, type your thoughts, and at the end of the day (or week or whenever you are free) review your note and develop your thoughts and ToDos.
Or just create a note named “Review”, open it with a simple text editor outside of obsidian and leave it open the whole day. Whenever you want to capture something you don’t want to forget, write it in there.