Okay I checked out your blog, and I think that random post can sometimes be the best. I love to hear others thoughts even if its silly or inspiring. So with that you can write about things that hit you that day, regardless what they have to do with. Writer's block? What's that? There is always something to write about, throw on some music and be inspired, write about someone that day and make them feel good. I believe in serving others through our writing. Hope this helps, oh and try not to be too hard on yourself. :)
You know, I am a newbie and I have that concern too. What I do is that I use Windows Live Writer and Make empty post with just titles or ideas and save them as draft. When I am ready to work with one of them I do it and publish. That way if there is a day I ran out of ideas, I have backup! And when I get inspired I do what I just told you with every single idea I have. :) Works for me!
My blog's a little different, because half my content is off news/events related to families, education or health, while the other half is day-to-day experiences. And I can tell you some days it'll hit about 5 p.m. and I'll be hoping the guys do something. :)
When it's after 5 and I'm still stuck, I'll try to think back over the past few days about what's been on my mind and write about that. Is something in particular stressing me out? What books have the guys enjoyed lately? Any new food fascinations or aversions, though I've steered clear of that one for a month or so because even I get tired of picky eaters. Anything funny they've said -- sometimes I'll even keep a running "out of the mouths" file and post it when I have enough collected. I haven't done that in a while, though -- not since I started tweeting, actually.
The newsy ones are easy to generate ideas for, though they're harder to write because I usually research at least a bit. If I surf around or read my inbox long enough, though, the idea will be there.
I think random posts are wonderful, actually! Sometimes it's fun to just write exactly what's on your mind, even if it's just a bunch of random things.
I keep a pad of paper and a pen near me at all times. When an idea comes to me, I write it down immediately. Or if my kids have done something funny, entertaining or just something I want to remember in detail, I'll jot that down too. That way, at the end of the day after all the kiddos are in bed, I can go back and look at my notes and I almost always come up with something. When all else fails, there's always a daily meme you can do! Those are always fun and it's also a great way to meet other bloggers!