Here is how my thought process broke down last year. I had a 3.59 and I knew I wasn't competitive at some of the top firms. I immediately knocked Williams, Cravath, and S and C off my list. But by the time you actually rank all the bids you really want and think you're competitive for, you still have slots left in a lot of cases. Thus, I ended up bidding some firms that were out of my reach at like 50 and indeed they did not pre-select me. If I were you I'd try to be a little safer at the top, but 50 bids is just way too many to use intelligently with a 20 interview cap.
I also remember that I hit the interview cap after pre-select fairly quickly and thus didn't have a lot of luck in the lottery because I wasn't allowed to participate. However, I picked up interviews outside the lottery and outside pre-select. I think, and maybe others want to comment, that the cap meant some top firms ended up getting turned down by pre-selects and thus had to fill their spots with people they didn't pre-select the first time. Depending on the firm, there are only so many 3.4+ or 3.5+ people in the class love. Career Services will throw you in there. I was thrown in with some firms I didn't really want to interview with because, for them to come back this year, UVa had to fill those seats. Bottom Line: you're always alive, sometimes just by blind luck.
I'm also thinking the "DC is death" thing may have been a little overblown last year. Other will have better insight. I had one DC screener and I converted it into an offer, I had 20 NYC screeners and ended up with 2 offers. Obviously that data is near useless, but there it is. Combine it with other data, make a graph, I don't care. My inference is also based on talking to other people.
In the end, OGI is a crazy and random process. I met some cool people and experienced some weird interview stories. Some things you just can't control for - like getting interviewed after lunch when the person is sleepy. I thought I totally nailed one interview with a firm I really wanted and it didn't pan out. Keep your head up, enjoy the delicious food, and realize that there is usually a little bit of reason to the interview. For instance, I didn't click with a lot of people during my callbacks. What did that tell me? Well, maybe this place isn't for me. No hard feelings. It's not always you, sometimes it really is them.
Schedule your shit EARLY! Several times I waited a day or two after getting a callback to schedule it, that is stupid. Schedule as soon as you can, duck out of class for 10 minutes if it's an 80 minute class that just started. As someone who was still going on callbacks in October, you do not want to go on callbacks in October. It's not only harmful to drag the process on, but it's bad for your chances of landing a job. In the beginning of callback season attorneys are excited to meet and interview you. By the end it's less exciting. You'll also burn out. On a related note - try to schedule back-to-back-to-back . . . callbacks. Spend a week in New York in September, it's fine. Flying back and forth to La Guardia twice a week sucks. You might be worried about missing class, but it's more time efficient to miss a week or two of class early on than to miss 5 classes in September and 1 in October. The travel time really adds up and going in and out ruins your flow.
Another comment is that in this next month you're going to read Chambers and Vault and make assumptions about the type of people who work at these firms and what their cultures are like. Who they are, what the personality is like, what the quality of life is like. Your assumptions will be wrong. It's not your fault, and it's not that you shouldn't do it. It's just that it's hard to access that information from where you sit and learning about firms is not that simple. Different offices and groups will have different personalities. I was lucky enough to go on a callback at a firm very near the top of my list, and everyone there was weird. I knew as soon as I left that I would never set foot in that office. I ended up taking an offer at a firm that was barely on my radar coming in. Now that I'm at the firm it is indeed what I was looking for, but there was no way for me to know that beforehand.
Also, I found career services to helpful but sometimes they're prone to "yeah, go ahead, shoot for it." If you have good but not great grades, below a 3.6 or so, don't interview with Sull Crom just because some guy 3 years ago landed an offer there. If you have a 3.31 don't bid on Skadden NYC because some chick, who did private equity for KKR for 7 years before going to law school, went to UVa then summered for them. Sure, it might happen, but try to play smart. Sometime I feel like CSO is telling me I could be the exception to the rule, but I'm probably not. This goes triple if you came straight through from undergrad and don't have cool WE.
Apologies for my likely useless and unedited post.