Step1
Take Notes -
Carry a journal, always. If a thought occurs to you, write it down! The first step to using your ideas is recognizing when you have them. Even if what you're thinking seems unrelated to your blog, write it down.
If it's something you're pondering on, chances are you'll be able to use it later.
Step2
Add to your notes -
After you write down a topic, when you have a slow point in a day, go back to it, and think about how you'd want to approach this. The more material you have, the easier it will be to organize your thoughts when you blog.
Step3
Apply your Thoughts -
At the end of your day (or whenever you sit down to blog), what do you think you'll enjoy talking about the most? The list you've kept could span from Holiday Decorations to Global Warming, so go ahead and narrow it down.
Choose what you'll have fun discussing in your blog. You can always set aside another favored idea for later.
Step4
Find Your Angle -
If you have a themed blog, you'll need to slant your topic to suit the blog. This is much easier than it sounds, just find out how your topic plays into the theme of your blog.
Tweaking my be in order. This could mean taking your topic and broadening it, say, from Holiday Decorating to Holidays in the Office, or it could mean narrowing it way down, to something like Holiday Themed Candles.
Step5
Designate a Time of Day -
Treat it like a professional obligation (especially if it is). If you create a habit of blogging every day after your shower, or while you're eating your breakfast, it's easier to get a blog out on a daily basis.
Step6
Plan Ahead -
If you take notes daily, on your days where you're busy, or forget your notebook, or are having a dry spell, you have back sourced material to work with.