Look for opportunities to add colour and edge. It could be a bit of neat description or an amusing metaphor, a nifty bit of dialogue or a pacy bit of action. I go through my texts with a highlighter pen and mark all the bits I think add pzazz. There have to be at least 5 on each page and if not, I add some. Ideally, there are many more than that. They may be small, but the accumulated effect is of energy and colour. (I hope.) Here are a few of mine, all of which I know I added at this stage of editing.
* He was wearing short sleeves, but the ghosts of leather patches circled his elbows like wreaths of pipe smoke
* A laugh dirty enough to plough
* Steve looked mildly surprised, not dissimilar in expression to a Hereford bull suppressing hiccups
* Dancing to the rhythm of the music (though not entirely with it), spiralling away like a drunken daddy-longlegs.
* A knife sat in an opened jar of peanut butter, like Excalibur waiting for King Arthur
And then when that's all done, sit back and bask in glory. Then start sending it out.