How to enable/include a particular category alone on your feed

I have been writing on various topics from Health to Technologies, iPhone hacking tips to Blogging tips, many a times my readers were requesting me to have an option for them to subscribe to some particular topics which I write, and some times I had lost some readers too for this same reason.Take this example , One of my reader was particularly interested in my GTD (Getting things done) posts and when he see some blogging tips or Linux articles he got distracted and tends to unsubscribe. To avoid this, readers can subscribe to that specific category alone so that he won’t be getting bored or distracted with any other topics.I am putting my extra efforts to categorize articles in a sensible manner.