- Take Credit
Assuming that you've been doing mostly nothing for a while, you're unlikely to have very much to show for it. But that does not mean that your supervisor knows or understands that. They might be perfectly ready to hear you describe what has been accomplished and think that you've done some important chunk of it. Don't worry. They want to believe that you're a hard working and enthusiastic team member. If you've been sitting in any number of meetings at all, it should be easy enough for you to create a list of stuff that has been done that you can present as being partially, if minimally, responsible for.
- Turn the Tables
Sure this is your mid-year review, but there's no reason that all the conversation needs to be about you. That would be so boring anyway! Remember the pyramid. Talk about the other people in your group. Start off by dishing out glowing praise for some of the people around you in the org chart and work your way down the list confidently until you get to the point where you can say quote-unquote off the record that that one person in your group that you're thinking of but not naming really seems to be unhappy. You might even be worried that this person is on the verge of, well who knows what they are on the verge of but I'll tell you that it can't be good. That sets a stage for you to review your manager's performance and maybe dish out a few glancing blows wrapped in patronage and pity for anyone who would try to get anything accomplished with such a group of clowns.
- Sob Story (or SOB story)
Every system, engineers will tell you, has a bottleneck, a limitation which hinders its performance. A completely valid topic of discussion for your review are those entities outside your group which hinder yours. Certainly these are not problems that your manager can have any direct control over (or they would already know about them, and we would have discussed them in section 2, above). But your focus here is to delineate the boundary between you, your group, and this outside entity which is the source of friction. You should have several instance where you've attempted to address these issues but been rebuffed by those groups not taking responsibility.
And with that, you should be able to fill up the hour allotted for your review. If you haven't you should either work on your rhetorical skills or just work on your, er, work. You should also have taken the care to schedule the review between two meetings which are critically important for your reviewer, thereby ensuring that your review meeting will start late and end promptly. By now you're already paying attention to water fountains and the location of public power outlets. Taking notice of how little details like this can work in your favor should be easy.