For me probably the one most valuable piece of gear i own for preserving different fiffs and melodies is a Boss Loop station i can lay down a simple chord progression or a complex one (one that's hard for little brains like my to remember) and then i can play around with riffs and soloing until i do something that i really like. Sometimes it may just be one or two certain notes or licks that really make it worth keeping. When i am satisfied i will then copy it onto my computer into my recording studio software and save it. And while you can create cool riffs and licks with the boss loop you are elevating your improvisational skills by leaps and bounds.