This is going to be a very quick tip for those of you who fall in the not-so-frequent contributor group.
Think of the last nine images which you upload. Carefully. Older users may already have noticed that these images are usually shown on your profile page in the "Latest uploads" bar before they are fully indexed. So, they're visible faster. Moreover, people might often search for an image but also decide to check out the contributor's portfolio. You have little control over the other bars with images, but when it comes to the Latest uploads - why not use it also to your benefit and present your best of the newest there?
How? What I do is pick nine images - the ones I think are best of my latest series, ensure there's some variety in them and upload them last. I first set all my other files for upload in FileZilla and once this is done - I upload the last 9 images. They may be reviewed at different times but normally would show up in the bar in the order they were uploaded.
So, it doesn't require much effort other than separating the 9 best of the batch and upload them last. They'll get more views much faster and at least as it has been with a bunch of my images - pick up sales in a similar manner.
I mentioned it in the beginning - this makes more sense if you have longer gaps between uploads. If you upload regularly you don't really need to care that much about it, but if it's a week or more in-between batches for you - give it a try for a month or two and see if it helps.
As it turns out - in some cases you just need to use the fingers on only one of your hands to keep track... Not bad.