Nothing goes together quite like BP and mood logs. I've been using one myself for about 2 years now (Daylio, holla) and it's had a huge influence both on my perspective of my disorder and on my management of it. As y'all know, sometimes it can be hard to think right with BP, and to remember things - even if they're important. And when you're speaking with your psych, it can be even tougher to find the right words.
Mood logs help organize whatever the heck is going on with you, so it's all neat and laid out in front of you. Now, I have days I forget to check in (that's a whole nother problem), and sometimes it can be hard to log moods honestly (I'm depressed again? really?) but overall, I believe mood logs are an essential part of clearly viewing and managing moods that can be so changeable and erratic. You begin to see patterns (such as seasonal ones), and are more in tune with your mind. Overall, mood logs bring a lil more method to the madness.
There are about a zillion mood logs out there, and once I found Daylio I was personally hooked on that one. But here are a few questions to help you decide which log is right for you:
Are you going analog or digital? Some people really like having a hard-copy of their log and writing by hand. Look into mood journals or bullet journals if this tactical approach sounds right to you.
If you're interested in something more digital, what are you interested in logging? Besides mood, there are other potentially valuable things to track such as sleep, water intake, exercise, etc. Is the app you've chosen attractive and easy/quick to use? You don't wanna pick one with an overwhelming interface.
Decide when you're going to log your mood. Trust me, the more consistent and precise you are with this time the better. I find that having it be part of my nighttime routine better ensures that I don't miss a day.
Decide why you're logging your mood. From personal experience, you won't make it far if your best answer is "it kinda seems like I have to." Really take time to think about how priceless this sort of self-knowledge can be, and the great things you can do with it. How it can help your self-awareness and mindfulness, and lead to more educated choices on your part.
I hope you find a way to track your moods in a way that makes sense to you, intuitively. I hope it strengthens your understanding of yourself and leads to greater self-compassion and acceptance re: your moods. I hope you look at the ups and downs on your chart and see Life, beautiful and painful as it may be. I hope you find this tool helpful on your journey!