what worked for me (it's also somewhere in my profile and stuff, but I'll summarize here) is:
- Apply to at most 3 schools per round
- Write your app for the school with the LATEST deadline in R1 first (in my case, Haas, 11/4)
- Refine that 1st app and then put it aside
- Work on your 2nd and 3rd app using the new found knowledge from the first app
- If you have time, go back to your first app and realize how crappy it looks (even though you thought you were done with it), refine that
- Come back to the 2nd and 3rd app and refine it even more. SUBMIT.
- Submit your 1st App (the one with the latest deadline) after some more refinement
Rinse and repeat for Round 2.
The benefit of this method is that you don't have ANY "throwaway" apps, and that all your applications can benefit from the knowledge you learn as you complete each app. The downside is that you need to give yourself at least 3 weeks to "complete" that first app, and at least 2 weeks for each subsequent app. Then you need probably 1 week to refine each app again before submitting.