1. Don't kill apps. Period. It doesn't work. Period. (I'm assuming you received the OTA update and are running 2.2). It actually kills the battery faster. Task killer worked on 2.1 -- they do not work on 2.2.
2. In Menu > Settings > Accounts & Sync -- disable sync for News and Stocks. If you have the HTC News widget on one of your home screens, disable it (this is a notoriously buggy piece of software -- there are tons of threads on it in the EVO forum). The Google News & Weather widget is superior. If you use the Stocks app, you can still update manually.
3. If you are running the FriendStream widget, set it to update every 3 hours (or more). If you don't NEED to run the FriendStream widget (i.e., you only use if for Facebook, not Twitter), then remove it and use the Facebook widget. If you remove it, disable "sync live feed" for Facebook for HTC Sence in Accounts & Sync.
4. Set the Weather widget to update every 6 hours (honestly, do you need your phone to tell you whether it is raining outside?)
5. Turn off GPS when you are not actively using it. Unlike other platforms (Blackberry), leaving GPS on actually kills the battery on this phone.
6. If you are using the Calendar widget, consider removing it and installing Android Agenda Widget (in the market) in it's place.
7. Set any other widget that syncs online (news, Facebook, etc) to only sync every 3 hours or more.
8. Disable active wallpapers.
9. Set your screen to Auto Brightness in Menu > Settings > Display > Brightness.
10. Set your screen timeout to 1 minute.
11. Dial *228 to update your Preferred Roaming List (PRL).
12. Consider turning off "always on mobile network" in Menu > Settings > Wireless & Networks > Mobile Networks. You should still received pushed emails, but to sync that a message was read or deleted you will have to manually sync the account.
13. If you are usually in a place that has wifi coverage, keep wifi on.
Bump Charging: this is an unfortunate term - it really means to "top off" the phone. Basically, when you plug the phone in for an overnight charge, it will achieve a full charge (the light turns green) and then proceeds to run off the battery again (not the AC). When you wake up, you can find that the phone is down to 90% or less because of this. "Bump charging" involves unplugging and then re-plugging the phone in order to get back to 100%. Some people turn the phone off then plug it back in; others simply reboot it then plug it back in. It makes no difference, but it does help battery life and does not damage the battery.