I have seen a lot of blogs popping up productivity, so I thought I'd write one too. It's going to be less specific than most and more on the general philosophy of productivity.
There are many books on productivity, read them all. If you can do 25 or so, each one might give one a little piece of information the other ones miss. This goes for anything, if you want to know about any subject, just read every book you can find on it.
Make it a focus in your life. There is a tendency in me, and I would guess many other people to be inefficient. I can't tell you how many times I've gone to the grocery store every day of the week to get dinner that night. If I would have spent just 10 minutes of planning, I could have bought dinner for the next 4 or 5 nights and save myself a ton of time. That extra 10 minutes seems like a pain in the ass at the time, but you're saving yourself hours in the future. I'm sure there is some evolutionary reason for this trait, but we have to consciously fight it. Always think about ways you can save time and use it more efficiently. If you are always on the lookout you will find many ways to make your life more efficient. To avoid not feeling like spending the time, schedule planning into your routine. This obviously goes for way more than groceries.
Eat right, work out, get enough sleep, be healthy. If you feel like crap all the time, you will have to use a lot of will power to get off the couch to get things done. If you have an over abundance of energy you will try to find ways to burn it off. Life is much easier when doing stuff is something you need instead of something you want. Don't eat too much in one meal, your digestive system will suck all your energy away.
Make to do lists every day. Not much else to say about that.
Change things up. Doing at least 5 things a day on my to do list everyday works great for a while until you are bored. Starting a timer and working for 2 hours straight, taking an hour off, etc... works great until you get bored. Keeping a 9 to 5 schedule works great until you get bored. There is no one special technique that you need that solves all your problems, you need to keep changing things up so you don't lose your motivation.
Keep your workspace clean. Your computer desktop, your actual desktop, your office, your home, etc... It's a lot easier to implement a plan when you know exactly what to do and where to go to get it done without searching through a huge stack of paper, files, etc. I find my mind feels cleaner when I'm in a cleaner environment.
Makes lists for routine activities. This works for me but it's one thing I don't think I've ever seen anywhere else. I have a list on my refrigerator on all the things I need to do to have a completely clean house. Removing any decision making on what to do next and just following the next thing on the list really makes it easier to do. Mentally it's easy to just think to yourself, I'll just do the first thing on this list, which takes like two minutes. 9 times out of 10 you end up doing the whole thing.
The final thing I want to say is it is a process. You can't just go to the gym for a couple weeks and then stop. When you stop your muscle mass and cardio go back down again. In the same way you can't read some blog or book and be perfect. You need to continue to read books, blogs, spend time thinking on how to improve, find new ways to keep motivated, etc. I think that is information that is lacking from a lot of information on productivity. You never solve the productivity problem, it's something you keep up, it's takes an attitude of constantly refining and improving your methods.