Just buy something.
The reality is that after awhile, it either lives up to your expectations - or, you find functional issues with it. Those will largely be it's shape, how it fits the hand, how it opens, how well you can withdraw, open, cut, close, and replace in your pocket. Do you want to do that one-handed? Do you prefer tip up or down? Will the thumbstud/hole placement work for your specific hand, or can you get used to it in a week?
Then there is discovering that the style you prefer in that knife is actually counterproductive to using it. Maybe the choil is in the wrong place, or you don't even like it. The butt of the handle is too high, or low. The jimping on the blade back too aggressive, or not enough. The handle material too rough, or slippery, because of the way it's been finished.
It might come down to it looking dinged and beat up, because the anodizing on the aluminum scales can't take the level of work put to it, they are too cold, or conducted electricity once too often.
If that sounds like a list of things an engineer would sort out during the product developement cycle, yes, that's the intent. After 45 years of messing around with knives, all those issues have cropped up, and a lot of us have come up with our own personal gripes and grails. The challenge is whether they will be as important on your list of priorities. Take a look - we don't all marry the same kind of wife, either.
EDC - here's what's on my list, I have no idea if it's practical for anyone else. Simple thumb stud or hole opening, a flat ground drop point blade, a quality lock that is reliable, G10 scales, open back screwed together construction, minimized internal liners, a lanyard hole, and the best possible blade to handle ratio.
Knives that do that: Spyderco Military's, the import Persistance series. Benchmade Vex, or 950 Risk. Strider SnG. Hinderer, or the Kershaw/ZT versions. The problem is there is still quite a bit of breadth in all that.
Best thing to do, take $150 in cash, hit a few knife stores, handle what you think is a good knife for what you want it to do. Actually putting it in your hand and assessing whether it's a great tool for you, or maybe, not so much. Then, use it for a year, and reflect on the anniversary? Did it live up to your expectations, or was their something more, and what exactly would that be?
After about 10-15 years, enjoy the sock drawer full of familiar knives and how they rank for you. You'll have a good start on what you like.
