I know what you mean, I look at some of my old application letters and I just cringe, what was I thinking to actually WRITE that stuff?? Just stick to the facts, your "narrow skill set" - what in, computers? if so, you're not expected to have an outside life or personality - your interviewers won't! Ha ha, just kidding, I know things are different now. Yeah, they hire pretty, but they still need the workhorses and they know it, they just don't like to admit it. Just stress your skills AND your easygoing personality and your ability to understand the written word - see, you have got it all!
ETA - I used the same smilie as the above post! it's an interview day miracle!