[HTC Sensation] damagedbits:
I've been flashing way too many ROMs over the years, and a lot of that time I've usually been the obnoxious bastard complaining that something went wrong, mostly because I got impatient and didn't go through the right steps pre and post flash. I don't claim to be any kind of genius on Android, but here's a few tips and tricks I've picked up over the years to ensure a smooth transition from ROM to ROM and avoid looking like an idiot when you break something.

1. Check on your SD cards health from time to time

You've probably had your SD card for a while, transferring new files and deleting old junk now and then. Just like any other gadget or piece of machinery, storage devices need maintenance from time to time or they'll stop performing so well and eventually die an untimely death - trust me, I've been there plenty of times. Luckily, your recovery (more than likely) can re-align your sdcards partitions for you. In Ext4 you can go right into the Tools section, check your sdcards alignment and, if needed, perfectly re-align everything in less than five minutes or so.

2. Don't jump right into setup after flashing a new ROM!

I know the feeling when an awesome new ROM comes out; you want to hurry up and wipe your drive, install it and jump right into setup without giving your device any time to adjust to everything you just bombarded it with. On initial boot, certain scripts and other various operations need to run in order to make sure everything's set in place and functioning as intended. When you dive right into the setup as soon as the welcome screen pops up, you make it a heck of a lot more difficult for Android to do its first few jobs and run the risk of breaking something or simply ending up with a ROM that performs under its threshold. I've been told that its best to give it about ten minutes for everything to acclimate, but if you can make it even five minutes without touching anything and then reboot your phone one more time before setup, you'll probably have a much better time.

3. Be nice to your battery

I know OCing and running bleeding-edge ROMs don't always ensure the best battery life but please, for your own sake, try to avoid charging from arbitrary levels. Your battery will live a much healthier and longer life if you're not randomly plugging it in whenever you get a chance. Granted, we don't always have the time to wait until it gets to 20 percent and then plug in for a full charge, but the more you can do something along those lines, the better.

My rule if thumb is make sure you're at 100 percent when flashing a new ROM, do at least one full charge cycle and then pick a level somewhere under halfway to charge at. For me, that's about 30 percent - and I try to do a full charge cycle every other week just to keep things accurate.

4. Understand that flashing a new cutting-edge ROM every three days isn't necessary, nor is it very good for your filesystem

If you're not a dev (and I'm certainly not) then there's no reason for you to flash nightly builds of an unstable ROM every day, unless you're experiencing major bugs and the update squashes them. I know; its a refreshing (albeit sometimes tedious) experience to get an ota regularly, but your filesystem and sanity will thank you if you aren't always putting unneeded stress on them.

5. Read what the OP has to say before flashing

See a new kernel or ROM you've been waiting for all your life? Your first instinct is probably to click through to devhost, download and flash right away without doing any homework. This one's pretty obvious, but read the list of bugs, changelog and preferably the first few pages of discussion before you put yourself in a position to potentially brick your phone. Its really a win-win situation; you have something to do other than twiddling your thumbs while the file downloads and you'll know all there is to know about what you're loading onto your device. It doesn't hurt to hit the Thanks button if you like the dev's work, either. :p

And finally...

*cue Wilford Brimley voice*

Make a nandroid backup, and make it often.

Anyway, those are just a few steps I've found scattered around the internet/learned to take to ensure maximum device performance and health, being a flashaholic and all. Just thought I'd post that here since I haven't seen anything else of the sort on the Sensation forums. Feel free to share your own routines and advice!