This is the one thing I find Asana effective for. Another option might be to repurpose issue tracking software - after all, it's basically just a to-do databas

This is the one thing I find Asana effective for. Another option might be to repurpose issue tracking software - after all, it's basically just a to-do database. I've also known people who use plain text files on a remote machine plus vim plus SSH. But software is just a tool. What it sounds like you really need is a system for keeping all these balls in the air. Without a system, no software is going to solve the problem of failing to remember you need to follow up on things. This type of work is something I find Getting Things Done very effective for. You don't have to rigidly implement everything the book prescribes, but it does offer a philosophy and a toolkit of processes that you can mix and match to keep your work organized. Once you have a process, you can implement it in OneNote or index cards, or whatever the heck else feels ergonomic to you.