I usually use pen and paper for putting down ideas and making small diagrams of my ideas and if I am showing my idea to my friend or intend to build with them I

I usually use pen and paper for putting down ideas and making small diagrams of my ideas and if I am showing my idea to my friend or intend to build with them I would use miro. Its a great tool Lastly if I'm out walking or an a train and have an AHA moment for an idea I would put that down in my phone notes app as a reminder