How do I implement the GTD system like David Allen or without technology or an app?

Paper can totally work. You need to find a way that fits the way your brain is wired. Look for the bullet journal, it's a clever way to use any notebook to get organised. You could take the paper logic of it to use your notebook as a gtd system.

I've been using the method for years and I always end up back on paper. I don't know why, but there is something to it that helps me set realistic priorities. I also now require two things for each project. One is a clear statement of when the project is completed, and the other is a measurable list of results. It's great for focusing the mind and saying 'no' to the right things. 'Results' differs from 'completion' in that it gets to the 'why' I'm doing it with some measurable targets. For example, if my goal is to reorganize my living room and dining room, I would define it as complete when everything that belongs in that room has a home and it is in it's home. A result could be that I hold 2 impromptu dinners for friends in the next 2 months with less than 20 minutes of cleanup time required before each dinner. Of course, that assumes the grocery shopping is done, and the barhroom is clean, but those are other projects ;-)6

Try using a plain notebook, and look into http://markforster.squarespace.com/blog/2009/9/5/preliminary-instructions-for-autofocus-v-4.html wherein you maintain one master list with 2 main sections: a backlog and an active list. You then work on all backlogged to-dos, cycling through them until they're done (or deferred), before getting to the active to-do items.

You might like using the product we're developing called Betabook. It's a compact portable whiteboard in the form of a book. The advantage is you get to preserve the value of handwriting without having to carry a whole notebook's worth of paper or worry about losing scraps of paper. You may find you still want to archive your todos or action items digitally, but using Betabook should reduce your "screen time" considerably. Have a look: http://betabook.co

+1 for paper. I have a Word doc that is several pages long with my different lists ("Next Actions, Personal", "Next Actions, Work", etc. I print out the lists every Friday after I do my weekly review. I keep a copy on my desk at work, and every time I complete an action or have a new task, I mark up the lists with a pen. I tried maintaining a 100% handwritten list but to do things right you need fresh lists every week and that's a lot of writing. I also have found that loose leaf paper is greatly superior to bound paper. I use the app AnyDo as an inbox. When I'm at home or out, I will scribble my to dos into AnyDo and then will reconcile with the lists later.

I suggest just a small notebook. Small enough to bring with you, but big enough to have full lists. Just create a page for each Context (Email, Work, Errands, Etc) and one for Projects (Change Bank, Mom’s Birthday, Hire New Intern..). From there, you review your project lists and put the tasks on the individual context pages.