For conventional writers and artists (as far as writers and artists are “conventional”), I think one cannot stress the importance of having a portfolio (which I label as “sample work”).
I mean I’ve seen lots of applicants (not necessarily in my job) for writing and graphic design positions. But honestly, please, don’t submit just your resume. Submit a portfolio. Of course if you’re a big-name artist and have one of your works on a billboard somewhere, that might not be necessary. But if you’re just starting out, it’s not that we’re denying your talent, but we’re honestly clueless with regards to what you can do. Shall we just base it on your name? The photo attached to your resume? Your alma matter isn’t going to help because there are probably other applicants who graduated from the same school as you did. And as far as awards and workshops go, if we’re not familiar with them, we can’t exactly judge your caliber. For all we know, the workshop or award you won is inappropriate to what we’re looking for (i.e. we might be looking for corporate writers, but the award you won was for a fiction contest, for example). The best way to showcase your work is probably through your portfolio, be it sample work or sample art.
For other occupations, the resume or CV might be your selling point. Anything else might just be supplements. I think writers and artists should get rid of this notion. It’s your resume that’s a supplement. Your portfolio is your primary selling point. I know some people who can do away with both, but that’s because they’re either charismatic people, have a good network of friends and family, or either started early in their careers and/or are extremely good at it that one only needs to mention their name to get someone’s attention. I’m not one of those people. And chances are, you aren’t either (if you’ve attained that position already, all of this is unsolicited advice). Which is why a portfolio is important. To be honest, I’m a shy person. Yet having a portfolio works to my advantage. I don’t have to talk about it. I just hand it over to my prospective employers (or clients, if you’re more of the independent type) and leave all the talking to my portfolio. They browse through it at their leisure (so I’m not pressured to give them a presentation under a time limit), and it’s something they can use as future reference (which gives hope for those who aren’t immediately hired). That’s not to say that writers and artists shouldn’t practice their social skills, but based on merit, nothing can best express your capabilities other than the actual work you come up with.
Ideally, a portfolio should comprise your best work. While more isn’t necessarily better, I don’t want it to be as thin as tissue paper, because I want to show the range of my talent and capabilities. Even if the position you’re applying to isn’t looking for a particular style of art and writing, submit it anyway because you’re not psychic and don’t know what your clients are looking for (i.e. just because you’re submitting work to a comics company doesn’t necessarily mean all you submit are comic art and scripts, but include poetry, portraits, photographs, fiction, landscape art, etc.). That’s not to say you don’t include comic scripts or art in your portfolio when applying for a comics company, for example, but do show variety and range.
Unfortunately, I haven’t been doing my homework. I have a portfolio, and while it has range, not all of it is my best work. I’m the one compiling my portfolio though so while not all of it is my best work, certainly none of it is my worst. Which is also an important lesson for starting writers and artists: don’t put everything in there. Similarly, either screen your works or edit them. Nothing is more embarrassing (and this has happened to me) when your prospects start pointing out typos and incorrect grammar in front of you. But on the other end, don’t lose confidence in your work. As I said, ideally, what should be in your portfolio are your best works. If I followed that formula strictly, I wouldn’t have anything in my portfolio. The point is to be critical of your choices, but not to be too conscious about it that you end up putting little, if any, in your portfolio.
Again, I’m a shy person. But when the time comes for me to look for prospective clients, I have a handy file (softcopy) that contains my portfolio (it’s a failing of mine, but having a hardcopy is essential as well). If I need to submit something by email, I just send it as an attachment. I’ve been doing it for the past year that I don’t have to be shy about it anymore. If you’re the type that’s self conscious, you don’t even have to look at it. Your clients do, however, so just send it to them. When in doubt whether it’s appropriate or not, just send it anyway. In most cases, something is better than nothing. I mean the worst scenario is that you don’t get a reply. I don’t think I need to elucidate what the best scenario is.