I also designed my own. I could, personally, care less about some of the technical details of the dive. Instead, I want LOTS of narrative space. I use the log to document the type of dive, the topography and the critters seen. I often go back to the same areas and I refer to this info. It helps me decide what lenses to use on my camera, what to look for and where to look.
I print out the page, take it to Kinko's with the dimensions I want (smallish), print a bunch of pages. Then I have them drilled for a spiral binding. When I go on a trip, I take more than enough pages to cover that particular trip only and have just that number bound. I take a printed photo with the trip name and date on it and have them use it as a cover for the log. Then, I have a clear plastic sheet cover the photo for protection.
It makes a small, compact and very professional looking log book that has exactly the info I want on it. I have a bookshelf where each individual dive log is.