Interesting thread.
We all have slightly different needs and approach it in a different manner. Here's how I do it.
First, I like one hand open. When I work in my shop, I find it useful. I also like a 3"+ blade that is sturdy enough for hard work. My answer is an Opinel N9. Bonus, it's super safe to one hand close, too. I does take practice to handle it one handed and it takes some TLC to tune the knife to be smooth.
EDC Pair by
Pinnah, on Flickr
I *hate* pocket clips and find they essentially close off the pocket for any other use. I prefer a lanyard on the end of the Opinel which makes it easy to get out. I also keep loose change in my RFP and generally find it easy to reach past the knife to get the coins.
I keep my money clip with drivers license and debit card in my LFP along with a key chain tool. I grew up with scout knives and love the functionality. I also like to whittle occasionally. The small key ring type tool handles this with aplomb and I carry it loose, in my LFP. The lanyard on it minimizes pocket ejects and gives me a fighting chance to find it in the grass.
I carry my cell phone in my LRP and use Cliff Jacobosen's idea for rear pocket knife carry by running a seam about 1/2 way up the center of the pocket. The essentially creates 2 tall thin pockets that keep a phone or knife upright. On the outer pocket, I don't notice it when sitting.
Bandana in my RRP.
As for everything else... I'm a backpacker and have been commuting with laptop for more years than I can count. I now feel unequipped if I don't have a small daypack or messenger bag of some sort with me. Call it a man purse, go-bag or whatever. Notepads, larger wallet with other cards, larger multi-tool, back up knife, keys...
EDC Back Ups by
Pinnah, on Flickr
This is stuff I don't on my body throughout the day. I can go find the bag and get what I need. So long as it is in the car, or in my office or in my house, I know I have access to stuff I need.
Keys.... I don't carry them and don't carry any knife of any sort on them. I hate them banging on the steering column, hate taking a knife on and off the ring and refuse to carry that mess of metal in my pocket. I keep a tiny carabiner on the key ring and when I must carry them, I clip them to a belt loop.
Good luck in your quest.
Bottom line, no need to give up traditionals. Consider swapping your modern tactical for an Opinel.