Although personal tastes vary, some very nice add on's to any survival kit are the following,
-An all in one eating kit (like a knife/fork/spoon combo tool, the titanium spork, and the lego locking utensil set, etc.). Although a proper place setting in the wilds or while surviving is silly, a good fork, spoon, or small knife (or preferably something that combines one or more of these) can be a very useful tool out in the wilds. Eating snake, rabbit, or other small game with your hands is acceptable, but sometimes (like with a wilderness stew, little bits of game or with live dangerous things you catch, such as scorpions) a spoon, fork, or knife can come in VERY Handy and make an excellent addition to most survival kits. My own personal preference would be something like the titanium spork as found here.
Lightweight, durable, non-meltable and all around useful for digging into a stew or digging a small trap for scorpions and other insects.
-A field "mess" kit with several bowls and small plates that fit into a small, lightweight compact space is also a nice add on to a larger survival kit. It's all well and good to find water, food, and wild edibles, but unless you have something to cook and eat it in... doing anything with them is somewhat problematic (although not impossible by any means).
I kind of like this set. It is good for a travel kit or for keeping around for picnics...
But it is useless for cooking over a campfire, and odds are that is what most of us are going to be doing while surviving, so I would recommend something made out of metal that you can actually boil water in, cook in, and eat in.
Something like this...
Would be more useful in the wilds, but adds bulk and weight to your survival or camping kit.
-A good sewing kit. Although heming up a dress, tailoring a suit, or sewing up some long pantlegs is definitly not survival priority, having a good sewing kit in your survival kit does add a lot. Nothing is more frustrating than getting a rip or tear in your clothing from all the brambles, briars, and branches you will be trapsing through, not only will it leave part of your body exposed to the sun or cold, but it also can ruin vital pieces of survival equipment (like a rain poncho or backpack). With a sewing kit, you can fix them and keep going without looking like you've been mauled by a bear. Speaking of being mauled by a bear, if you do happen to get major cuts or wounds in the wilds, a sewing kit can also be used to stitch wounds closed and in a pinch, they can be made into a primitive fishingline and the needle can be bent into a hook (although you wouldn't want to try and land anything much bigger than a bluegill or other small fish with it).
-Personal grooming items. Although a good bug out bag should have a toiletry kit with it, a good travel sized surivial kit should also have a couple small toiletry items in it as well. If you are surviving with another person or a small group, believe me, they will thank you.
A small toothbrush and a travel sized tube of toothpaste, a small thing of dental floss, breath mints, wet wipes, sealed packs of degradable wipes, degradable travel toiletries (which has little sheets of soap that dissovle in water that you can use to wash your hands). Small bottles of hand sanitizer, etc. If it makes you look, feel, and smell cleaner, odds are it will help stave off bacteria and helps keep you healthy. Some examples of good personal care gear are.
And no, I am not trying to push stuff from Thinkgeek, just trying to show good examples of what I am talking about. You can usually find really great items from most outdoors stores, gas stations, and dollar stores for a much reduced price and of comparative quality
So whether you go expensive and hi-tech or go basic and low-tech, whatever your style or price range (believe me, my price range is REALLY cheap so never feel bad about being a penny pincher, part of good survival is knowing how to manage your resources), you can find several right add ons that will truly make your basic survival kit, into a deluxe survival kit.
Until next time on Good Survival... now if you will excuse me, I have some french fries to eat.