Gonna 1) totally agree w/ these. (I could do them all, but won't.) I hate the lack of response (though I do expect patience to some degree). Nothing annoys me when I get a solicitation from a would be prospect and they want me to quote $ and results w/out answering a single question. I just tweeted a post about the HR fail of not replying to applicants, even w/ a form email 'no.' 

Now 2) I'm gonna flip it around a bit. I make bad impressions - not by being late or rude - but by being me, by being transparent, WYSIWYG. Like w/ your COC experience, I don't 'present' well b/c I am a solo consultant one's that struggled. I'm judged and dismissed b/c I don't have the trappings of "success," never have. Whether looking for clients or a applying for a job in-house, my experience w/ my small business clients is deemed "small," my struggles a failure. Yes much of that's on me but at the same time, leaves a bad impression when I see people judged and pigeon-holed in this way. Everyone makes mistakes even tells questionable 'jokes' from time to time, but that doesn't make them less. We're all more than our job titles or companies or the tweets we share; IDK I'm guess I'm saying we need to make good first impressions, but we also need maybe a little benefit of the doubt, a grace period too. FWIW.