Software of manual?

Hello my fellow event planners. I have a question for all of you. When planning your events, whether it's a wedding, meeting, or other type of social affair, do you use computer software to help you with your planning or do you do things manually? If you use a software, which one do you use and why? How is this software beneficial? For those who have tried different software programs, what were these programs missing in order for you to be most effective to your clients??? Any help would be greatly appreciated!