Observation is one of the most important skills a writer can possess. Keep eyes and ears open for conversations, settings and people that may inspire screenplay ideas. Izzy Frost, a Hollywood screenwriter and script editor, suggests carrying around a tape recorder (many cellphones have a voice recorder) or notepad to jot down ideas as they come to you.
Sit down with a notepad and pen, clearing your space of distraction. Set a timer for two minutes. In those two minutes, write down all screenplay ideas that come to your mind. Use as few words as possible, writing down as many ideas as time allows. Think about news stories you have heard and funny situations or characters you observed. The goal is to let your memory flow without judgment or censorship.
Go back through your two-minute list and circle at least 12 ideas that most excite/intrigue you.
Explore each of these ideas further. If one idea is a character, put the character in a different setting and situations. If an idea comes from a story you have heard, explore the outcome if different choices were made by the characters in the story. See how far each idea takes you, and do not throw out any ideas.
Research your ideas. Go online or to your local library and learn more about the setting, character or situation surrounding your ideas. Explore various places, events and historical periods that may help you expand on your initial ideas, or provide the basis for new ideas.