When the idea strikes, take a moment to write it down. But don't wait until you get home to work on it. Find ways to use spare minutes. Use a phone notes app or other device. Or an old fashioned pad and pen. Write when waiting for others to show up for a meeting, write in the doctor's waiting room. Write on the bus. Use a dictation app and dictate it on your drive home. And for those evenings, make writing the thing you do first, even if just 5-10 minutes.