I keep a rolling portfolio – I think it’s probably the best thing for any artist actively looking for work.
I figure you’ve gotta refresh your portfolio at least once a year (actually you should probably refresh it between every convention) that way, should you see an editor for a second time you’re showing them something brand spanking new (and lets face it if he didn’t like the stuff the last time, why would he like it now?).
Some general portfolio advice I’m sure I’ve mentioned before:
All you need is a decent half a dozen consecutive pages (maybe three from one story, three from another – but certainly not six from different stories). I keep more there, but only cus I like to show friends what I’ve been working on and my portfolio is the best place to do this.
Make sure the work is complete. If you want to only show pencils, that’s fine (although 2000AD would probably prefer pencils and inks – ymmv). If you’re showing inks make sure you have pencils of the pages with you (and make sure the pencils you’re showing are by a pro – inking over your own stuff or another non-pro [don’t like the word amateur] is a bad idea – it’s best if it’s work the editor is already familiar with). I’ve seen lots of work where the work is superb but incomplete (pencils half finished or just abandoned – pages with incredibly detailed figures but no backgrounds either pencilled or inked) and trust me on this one, that bloke in the queue who is nowhere near as good as you but has completed pages, and is easy going *will* work before you – if you don’t finish your artwork.
A note about personal hygene and personality: yes, to a small percent it’s not about how good you are, it’s about how well you get on with your collaborators and the editor. Conventions are smelly, sweaty places — always too hot with no air conditioning. Before seeing that editor, before getting in that queue make an effort to not smell bad (I’ve sweated at enough cons to know that this can be tough). It’s true that drawing comics is one of the few jobs were you can be entirely judged on your merit rather than your personal hygene, but that’s only true if the editor never meets you.
Personality: I’ve never actually seen this happening, but arguing with an editor over the quality of your work is a no-win situation for you – he’s either right in which case you’ve got some good solid advice you can work on or he’s wrong in which case arguing an editor into publishing your work is the equivalent of Sisyphus pushing a boulder up hill.
Make sure the work is relevant: what to draw for 2000AD? turn up either with some Dredd samples or some work which is in a 2000AD ‘house’-style (if there is one). As a rule of thumb, the more radical your art style the more you’d better be doing a Dredd sample in that style. DC/Marvel AFAIK are less forgiving – if you wanna show stuff to the Bat-Editors make sure it’s a Bat-Sample (course you could be smart and draw a sample with Wolverine and Batman in it in which case you’ve two basis covered – but this is no use for Vertigo…)
And… that’s all I can think of.