It's easy to feel busy, without actually achieving very much. Checking email, taking calls, combing through analytics - all are time consuming, all could be considered work, yet I've found them to have limited impact on my success.
So I try and track what I've done each day. That way I can be honest with myself and how much impact I'm having. Here is the methodology I use.
Daily Journal - I write about 700-1000 words each morning covering what I've done and planning out what I plan to do. 750Words does a great job of providing a place to write privately. It's a creative exercise and gets me thinking. The most important aspect is going back over what I did the past day and putting it into words. That process ensures I reflect on what I've done.
Logbook - When I finish a blog post, have a meeting, push a new feature to production etc. I mark it down in a logbook. I have a list of possible tasks with a bunch of boxes next to each item which I color in when a task is done. The logbook is broken down into weeks so I can easily see how much I get done each week.
Points - I've talked about this little productivity trick here, which I recommend you read. I use it on and off, usually when I'm stuck in a rut which I need to get out of. It's very effective but can be quite draining.