I'm very much new to this writing malarkey and over the last few months various ideas for stories have popped into my head and I now have a total of six floating around my brain. Some of them might end up as subplots within the same manuscript or might end up as separate manuscripts, if indeed they ever make it to manuscript form! I'm open to how the ideas might develop and jotting ideas down as and when they enter my head, rather than working on characters, plots and settings one story at once. I'm finding it hard to keep track! So far I have a spreadsheet (I know, cool and creative ;-)) of the setting, main character(s) and a big narratve event that takes place in each story. I'm wondering if there is any other effective way of keeping track of multiple plots or subplots
Well, one way I dealt with subplots is to write each one as a different story with its own line breaks. Then I can copy-paste scenes around as I want. Another idea may be to make a timeline of all the events and how they interact. This is generally a good idea no matter the story you write.
I found Scrivener enormously helpful for this, due to the way it gives you oversight and lets you tag and categorise individual sections. You can tag all scenes related to a certain subplot, all scenes involving a specific character, etc.
I tend to get old fashioned and use paper to plot out my novels using a list of 'happenings' before I start writing. After jotting down each happening/plot point/scene on either a slip of paper or recipe card I shuffle them around until I find they sit where I want them to. You could color code with dots to reference different characters or plot lines and that way you could visually reference their appearances and shuffle accordingly.
Start with writing down any idea that you have immediately in a notebook. Sort these bits into stories at your leisure. I'm not a planner, but I wish the following would work for me: Once you know which story you want to focus on and have a decent stack of ideas that belong with it, write them on post-its and glue them to a big sheet of paper (C3 or even bigger). That way you can see where they fit together into a proper arc and you can move them around easily. Fill the empty spaces in between with appropriate scenes. Use different coloured ones for character development, than for plot scenes, than for global/political/social events that might happen during your story. Or you can mindmap this stage. Or use scrivener, or a scene board. Or whatever method you fancy so that you end up with a cohesive plot and character arc. For the small-scale planning, I found a dedicated notebook useful (one of those where you can make appointments for each day) to mark plotpoints so you won't loose track who does what on a specific day. "Wait." Paul glanced around uncertainly. "Haven't you had your birthday last month?" "I had." Pauline blew out the lighted candles and said, "You're a tad late, my dear. Mind you tell me why you baked me a cake and the room is decorated with 'Happy Birthdays' now?"
Break down all plots into scenes. Sort plots & their scenes into the columns of an excel file. One scene per cell. Put scenes that happen "parallel" to each other in the same row. Leave rows empty if a plot has no scenes happening in a specific time where others do. You can use a paint brush to colour cells for specific POV characters. That's how I (try to) do it at least.
Personally, i write everything down. Every inspiring idea that I feel i could write about gets jotted down. My stories are the same. I have a stack of standard school paper with notes. Many pages have many things crosses out too. It can get messy, yet it's worth the trouble in the end. I'm notoriously bad at remembering inventory and have frequently forgotten important items. Now i can reference item lists, character lists, points of interest, and a variety of other details i need to keep track of. Be as crazy with it as you want and always trust your gut.
Have you tried using Trello? I use it to break down my stories into scenes/plot, and you can move them around like electronic post-its. You can even assign them colours, so you could keep track of each plot by assigning them different colours.