Knives are as unique as the people who carry them. What you ultimately decide to carry is going to depend on a couple of different factors. Stop for a moment and ask yourself these few simple questions:
1. What is my intention for carrying a knife?
2. Will I use and carry my knife everyday?
3. Is concealment an issue or against the law?
4. What about fixed or folding blades?
Now that you have asked yourself these questions, let me explain the ins/outs of each. By reviewing these, you should have a better understanding of what your individual situation calls for.
What is your intention for carrying a knife? Is it going to be used primarily for work or for protection?
If you answered work, then probably something with a folding blade and good locking mechinism would suit you. Lockback folders worn on the hip are still popular although the invention of (legal) spring assisted opening and pocket clips have become all the rage. Brand is personal preference but make sure that you buy one made with a quality steel. I will be discussing blade steels in another guide. Kershaw makes several popular brands such as the chive and speedbump.
If your intention is protection, then you need something lightning fast, razor sharp, and uncomplicated. Most professional instructors will tell you that a fixed blade is the way to go here, and so will I. K-bar makes a knife design to fill everyones protection needs. From the military standard K-bar to the new TDI last ditch boot knife. But if for whatever reason you just don't feel comfortable carrying a fixed blade, then you might want to check out an auotmatic. Boker and SOG both lead the field in these designs. They're fast, safe, and very reliable. All the top things that you need in a defensive type weapon.
Will you use and carry your knife everyday? If you are like me, and many other folks if I might add, Then you won't leave the house without your knife. It's every bit as important as your wallet or car keys! Because of this, you will definitely want a knife that is light and comfortable. Along with the weight factor, you will want clean, rounded lines. Here, Gerber is an excellant choice for me. They make both a ripstop and paraframe model that have skeletonized aluminum handles. They are light, very light. And best of all, there are no sharp or abrupt edges to catch in your jacket or pants pockets.
If concealment is an issue that you need to be concerned with then look for something 3 1/2" or less in closed length. Pocket clip or no pocket clip is up to you and your specific needs but remember that total concealment can only be had without one. Don't let this deter you though. If you feel that you still must have the piece of mind that comes with a pocket clip than I suggest that you check out SOG's line of low carry knives. This company has finally come through with a grande finale. They have moved the pocket clip to the very end of the handle, almost off the handle. This, in turn with shortening the length of the clip, makes these knive all most undetectable.
Hopefully now that you have read my guide, you have a little better understanding as what to carry and when. Please keep in mind that these are largely my own opinions and thoughts. Based on my years of experience with carying, handling, and selling knives, I feel that these tips will help you. Always remember that knives are as unique as the people who carry them!