The purpose of a checklist is to reduce error in commonly repeated activities. Do you use your own or a generic version for your aircraft?
Flying without a checklist is like playing golf without a putter… Seriously, it makes success that much more difficult. Once you have been flying for a little while, most flights are a series of similar repeated activities above different places.
Pilots do the same things over and over in different airspace over different land formations. The purpose of a checklist is to reduce errors in commonly repeated activity. As an aside, I highly recommend every pilot read, “The Checklist Manifesto” by Atul Gawande. Dr. Gawande is a surgeon and checklist evangelist. He uses the history of aviation checklists as one of his examples to convey the importance of checklist usage. This history of checklists as well as checklist usage in construction, cooking and the medical field make for a compelling read. I’m sure that after you read the book you too will see the true value in a checklist for many activities.
Every time a pilot uses a checklist, they are successfully reducing errors in their ways. As a result, the simple use of a checklist increases safety in a pilot’s flying. So I leave it to you, why wouldn’t you want to increase the safety in your flying?
Don’t be afraid to make your own checklist either. Chances are you are flying an airplane that has a few hours on it. It is likely that there have been some modification made- new radios, yoke mounted GPS, etc… All of these things can be accounted for in your own personally prepared checklist. It would be very wise to consult others as well as the operating handbook for any aircraft when preparing your own checklist. A checklist made with an error, will cause the error to be repeated each time. The best way to avoid this is to test any checklist on the ground, have another pilot observe the checklist use and make recommendations for edits and remember that the manufacturer’s procedures should always be the foundation.
As equipment is added to an aircraft the pilot will begin to incorporate that piece of equipment into their flying. Eventually depending on that item for a specific task as necessary, whether it is the use of a new radio to pick up weather information, a new GPS for navigation or a new autopilot for flight in IMC, all of these items should be reflected in the checklist that a pilot is using. When an aircraft is changed, so too should the checklist used when flying that aircraft.
Generic checklists are good and usually “get the job done,” but that is about it. If you are a pilot that employs the autopilot regularly (I am not), the autopilot test and configuration should be reflected in a checklist at some point, rather than simply a memory item that you rely on yourself to remember. Manufacturer procedures should be the basis, but cockpit flow/organization and modified equipment need to be included in your procedures too.
Armed with and using a checklist, your own or a generic version, you can fly content knowing that you are reducing errors in your flying!
-Fly Safe, @MTElia1B9
Review Before Flight 
I am a big believer in checklists. They have kept me from making a mistake or have been vital in capturing an error. But, the checklist has a proper use and an improper use.
The checklist is just that, a list that confirms the proper placement of all the appropriate switches. It isn’t a “To Do LIst.” I have seen people not move a switch until they read it on a piece of paper, that is relying on the paper to tell you what to do.
I think the best way to attack the preflight/post-flight or whatever flight is to know what to do and move the switches. Then grab the paper and visually check your work. If you miss it, then fix it. If you got it all then press on.
Especially in GA, I think a pilot should have a modified checklist. When a pilot sits down and truly examines their flight deck, what they need to do, and when it needs to be done. They are being a active participant in the flying process. They will develop their own flow and will ensure that everything is covered. The only danger is that their flow may not work in a different airplane. But as long as they recognize that, all is well.
Great post.