Writer's Fallout Shelter

I wasn't refering to the whole roman numeral outline of yesteryear. LOL I can't do that because it's just annoying. I guess what I mean by outline is someway putting down the major plot events that I want to happen. I just feel like I get an idea and then don't plan it out well and often I lose the whole story because it's not well planned out. This hasn't happened with the manuscript I'm currently working on but I think I did more planning on it. It's just on bunches of scrap paper.

I'm trying to get ideas on how to better organize myself and my writing so that I don't feel so out of control when it comes to it.