I have spent many years on working with optimization of life and work. Have read/practiced most of the techniques from the old time-management stuff for 15 years ago until the most modern philosophies and tools. Dependent on where you are in your development, let me give you a quick advice!
Search beats categorization 100% of the time
Most of the people reading GTD books or similar effectivity books very quickly pick a tool and start coming up with categories, tags, folders, projects etc etc. Misunderstand me correctly! I have done all that as well. Many years after I have found that it is all for nothing. STOP doing all that.
All you need is 2-dimensional order in time, space and a damn good search tool
Using EverNote, you have few notebooks (order in Space), you have the attributes (order in time) and you have a strong search tool that OCRs your pictures for you. I have learned that most of the categorization is in vain. As you evolve and get better, you will change and your categories will get smarter and more meaningful. This is a fact that took me many tools and much hassle to understand.
This is why having a tool that will let you do quick and complex searches better than having many features, projects, categories & bells and whistles. Look out for a blog on how to search in EverNote and using attributes.
A hint, you can get your EverNote searched by google. When you search on google, you will get your evernote search results on top of the rest. If you have a plug-in for your browser, this would be part of the settings for that. I use Chrome for Mac and it works just fine!
Even if you don’t use EverNote, get to know how to search your note-taking tool. If you don’t have one!!! GET ONE NOW.