To begin with, you need to be sharp and remain still. Keeping your movements to a minimum will reduce noise and the chances of being seen. A great way to do that is to have a smartphone and two apps: Weather Underground and Fishidy. Weather Underground is essential for several reasons. It has doppler radar that will show you if a storm is tracking in your precise location, so you can be sure that you're safety isn't in question (that's always a great place to start). WU also pulls data from millions of weather stations all over the globe, so you can be sure to get predictions for the week that are as close as possible to where you're planning to be. I can't tell you how many times I've had people tell me "weather I hadn't anticipated ruined my trip". This app will absolutely reduce that risk.
Fishidy is also a great way to take a closer look at places you're very familiar with. Lakes and rivers are often changing, and there are many times when you'll catch a fish someplace where you didn't think you would. Maybe it's a certain depth, or a transition area that you didn't notice before. Now you can go and find other areas like that one and have some new places to check the next time you go out. Imagine how closely you can examine a body of water while you're sitting uninterrupted in a tree for 12 hours. It's hard to find the time to do that under normal circumstances, and even when have the time it's difficult to force yourself to do it.
Now I know that some people are saying "no way my battery will last that long". You're right. No cell phone battery will let you look at something with screen resolution that high for 12 hours. But Snowlizard has a case called that SLXtreme that will protect your phone and charge it. The case is completely submersible, and has a strap attachment (below) that will not only make it float if you drop it in water but it also acts as a pad so you can wear it around your neck without it being uncomfortable when you need to be instantly hands free. But the real advantage to this case is the battery power. When your cell phone is about to die, simply press the button on the back of the case and it will charge your battery back to full while you use it. The four lights on the back will tell you how much power the case has to give (4 lights equals a fully charged case). My SLXtreme has fully charged my iPhone 5 twice on one full charge, more than enough battery life to keep me doing research all day. And if that's not enough, there's even a solar panel on the back of the case that will charge it in the sun. The SLXtreme is available to smart phones as well as tablets, so you're covered no matter what you decide to use.
The last thing you need is to be sure to be warm and dry. I wear my Stormr Stealth gear and it gives me everything I need from a camo suit. I'm warm and dry, the Real Tree Max4 blends into any background regardless if I'm hunting trophy whitetails or geese, it's also dead quite so I can draw my bow without fear of being heard like other noisier jackets.
So there you have it. You're a hunting and fishing, weatherproof ninja ready to take on the outdoor world and staying one step ahead of the competition.