Think of your complete survival kit as something that should evolve and change according to your needs, rather than as something that you assemble once and toss into your pack each time you travel. Survival is is situation specific, and certain tools that may help you in the Arctic or the boreal forest will do you little good in the desert or jungle.
And as you'll soon see, different forces are at work in different areas. Ignore them at your peril. If I'm going tripping in the boreal forest of northern Ontario in the middle of May, the first thing I know I need is bug netting, which is specific to that region and time of year. Do I need to pack bug netting if I'm skiing across the Arctic tundra in the middle of November? Nope. It's important that you take these factors into consideration before every trip.
Arid Regions, Deserts and Canyons
Acquiring water is paramount when traveling in these areas, so your survival kit should address this critical fact. Make sure you carry a clear garbage bag in your kit in case you need to construct a solar still or vegetation still. A long, thin drinking tube is useful too. You might also consider carrying a small trowel or collapsible shovel to make digging for water easier.
Boreal and Other Temperate Forests
Blackflies and mosquitoes were reputed to have driven many of the early Canadian explorers insane. So I highly recommend bug netting for any region where you expect to be dealing with insects. Why netting as opposed to bug spray? Several reasons. Bug spray is bulky and heavy, whereas netting is light and can be folded to take up every little space. Also, while you will eventually run out of bug spray, your netting will last indefinitely, provided it doesn't tear -- and even then, you can repair it.
You may also consider taking along a bug shirt and bug pants, a variety of which are now on the market.
The Arctic and Polar Regions
Most of the drinking water you'll find in the world's polar regions comes from snow and ice, which is notoriously devoid of vital mineral content. This deficiency won't hurt you over short periods of time, but over the course of a few weeks it can begin to seriously affect you. You can offset this problem by carrying mineral tablets, which can be either chewed, or dissolved in drinking water.
In summer, bug netting is a vital addition to your survival kit. And in the spring, sunglasses will protect your eyes from snowblindness, which can result when the sun reflects off the snow all day and night.