[AT&T Samsung Galaxy Note I717] littlewierdo:
The three major battery drains are screen, phone calls, and the LED on the back of the phone (for the camera flash). Ive done alot of research, most everything else on the phone is pretty battery friendly but you can manage out another 10-20% of battery life in a 10 hour period by following numbers 3-8 below.

One other note (no pun intended), the battery monitoring on the phone is backwards in that, it drains faster the higher the battery is (ie. 100% to 90% is a much faster drain than 30% to 20%). On most phones, its usually the opposite (100% to 90% is much longer than 30% to 20%)

You can purchase several apps to automate some of these, Tasker is my personal preference but it does have a steep learning curve, but it will allow you to do any sort of automated task you need. Less steep is another popular app, Juice Defender. While not nearly as feature rich as Juice Defender, it features a very user friendly interface that is very easy to understand. There are others as well, but these two are the general standard people use.

1. Set your screen brightness as low as possible.

2. Set your screen timeout to as low as you can handle (especially if you dont / forget to manually kill the screen), screen timeout time 'can' be important even if you manually turn the screen off yourself because occasionally, the screen will turn on by itself (usually 'older' apps written for earlier versions of Android that required the screen to be on for wifi to remain active).

3. Turn radios off when you dont need them (gps, wifi, bluetooth, wireless data, etc).

4. (Requires root for stock apps, the app Autostarts requires root, the app Titanium Backup requires root) Use the app Titanium Backup to remove any apps you dont use (or alternatively you can use Titanium Backup either 'freeze' them or use Autostarts to prevent apps from ever starting). Unfortunately, all of these require root for stock apps. The preference for stock apps if you are on stock is to use Autostarts, the next best option is to freeze apps using Titanium Backup. I dont recommend removing stock apps as it makes the process for updating via the official channel (ATT) require flashing the phone with a stock image in order to allow the phone to update.

5. Set any apps that 'phone home' (weather apps, email clients, etc) to do so with as long of a delay as possible (ie. set the weather app to 1 hour instead of the usual 15 minute window to get updates).

6. (Requires root) Lower your processor speed. Very few tasks require anything close to the capability of the processor speed the phone is capable of so limiting the speed a bit can help.

7. If possible, turn your phone OFF when charging, this will allow the phone to fully charge. Trust me, Ive researched this specifically on the Note, it doesnt fully charge with the phone ON. You can use the volume buttons to temporarily turn the screen on (when the phone is OFF but charging) to see what the charge level is.

8. (cpuspy requires root) Use a decent battery monitor, I personally use Battery Monitor Widget Pro (by 3C) to monitor exactly what is causing the drain (make sure you get the right one as there are multiple versions on the market, look for the one by 3C), this handy app specifically logs everything going on with your phone (power wise) as frequently as every minute for the duration that you have the app installed allowing you to look at and review graphs, charts, and analytical data in order to really determine the problem. Cpuspy is another optional tool to determine if your phone is going into deep sleep but Battery Monitor Widget Pro will tell you what you need to know if you spend the time to look thru the data.

9. Keep apps current (updated) via the Playstore, Menu button, My Apps. Many apps such as Google Maps have significant improvements to battery life if updated. Many of the stock apps can be updated but require manually searching for each one, tapping on the app, then tapping the install button. Note that once an app is manually updated, you no longer need to search manually to update them in the future, they will show up as 'Installed' under My Apps. Alternatively, if you have Titanium Backup (requires root), you can link all the apps on your phone to the market which will allow all of these apps listed below to be listed under the 'My Apps' in the Playstore (which will allow you to tap 'Update All' button instead of manually searching one by one for each).

Stock apps that can be manually updated:

Adobe Flash Player

AT&T Navigator: GPS navigation

Featured Apps (Phone)

Gmail

Google Play Books

Google Play Music

Google Search

Kies Air

(Google) Maps

Media Hub-ATT 4G Smartphones

S Memo

Samsung Apps

Street View on Google Maps

Talkback

(Google) Voice Search

Youtube

YP Yellow Pages & Gas Prices

If none of the above helps, you may have to look into buying one of the three options below (all available on Amazon).

1. Extended battery (Seido is the only brand I trust). With the Seido battery, you can get more than twice the battery life of the stock battery. The negatives are steep however, starting with the price at $80, it doubles the thickness of the BOTTOM half of the phone (look at the screenshots carefully), replaces the stock back cover so the battery will fit, and the phone weighs a bit more. Also, (IMPORTANT), BUY THE RIGHT BATTERY FOR THE CORRECT NOTE!! You are looking for the i717 version of the Note or the ATT version of the Note. Do NOT buy the N7000 model of the battery (also sometimes referred to as the 'international' version).

2. Purchase a battery pack. There are several out there, Duracell makes one, they basically are a small square / rectangle shaped 'box' generally smaller than the Note itself with a USB plug on them, just plug a USB cable into the battery pack and the other end in your phone. When you have access to power, plug the battery pack into a PC or wall charger with a USB cable and recharge the battery pack. These are pretty cheap, generally ranging between $20-$60. The negative is, you have to carry around a small battery pack and a USB cable and requires either keeping the cable plugged into the phone while its charging in order to use the phone OR dealing with unplugging the phone.

3. Purchase a spare OEM 'style' battery AND a phone charger dock that INCLUDES a spare battery charger (otherwise, how are you going to charge both batteries at night without having to remove one battery from the phone to swap in the second battery to charge it). When you charge your phone, dock it and drop the spare battery in (generally behind the phone) and it will charge both. Pricing is around $30 for a dock with an included battery. Unlike the extended battery mentioned above, you do NOT need to worry about which 'version' of the phone you purchase for, the docks and OEM style batteries are the same between the two different phones (i717 / AT&T Note vs. N7000 / International version). The negatives include having to carry around a spare battery and having to power down the phone and reboot it in order to swap the battery.