Complexity has a high value. It offers friction - and simplicity is one of the most complex concepts I can think of. One needs to boil down quite a few bits of the puzzle to finally "crack the code". I am with Paul though - there is no code. That´ll be too easy. Not enough friction.
Simplifying does have very positive effects too. Less "stuff" to carry around. Your fly-tying kit can be much lesser. No more 50 shades of olive ...
So here is my approach to a fly tying workplace and how this translates to the tying kit.
I like to have an uniform surface under the materials, and in my view. I used to be really set on dark for long time, but I have experienced that a really clean white surface works very well too, sometimes even better. It really helps when trying to focus on the fly in the vice. A busy backdrop confuses the eye and is tiresome.
Try to make sure you have enough light when tying. I found a nice daylight lamp with a magnifying lens for rather small money. That lamp does not travel well. So I needed a better solution when travelling. So many places I stay, I´d say the majority - does have windows. The Vosseler Vice can be attached to the window glass. That is really brilliant. Another option is a mirror. In Hotel rooms you can take the mirror off the wall. Put it back and clean it well, otherwise you have the DEA on your heels rather quickly.
I mostly tie with very thin Dyneema in white. It is very hard to break and the thread is mostly a means to hold the materials. Of course one can use thread as „tying material“ as well which results in a different choice of thread based on the fy designs various parameters - as in North Country Spiders for example. So there is not much need for 50 shades of olive in your thread collection either.
a set of small, very sharp scissors / a larger pair of scissors for cutting rougher materials
bobbin holders - it is handy to have two at least. It is essential for some patterns, and can be a life saver when one thread breaks and you need to continue tying without having to redo the whole fly
material clamps - regular paper clips sold in office supply stores are very sufficient for the job, however - there is several specialised clamps and even clamping systems on the market.
knotting tool - I use a simple version, or my fingers
a piece of velcro or an old toothbrush for roughing up the flies
fly tying vise
The vise is a tool holding the hook. In the older days flies were tied on hand, meaning by holding materials and the hook in the hands without any vise. A vise is very handy though. In my mind it has two main functions a) holding the hook and b) support the hand which is offering the material onto the hook. I prefer vises with pedestals. Clamping a vise to a table did not work so well for me, but this is personal preference really. The drawback on pedestal version is the weight. So at home I work on either a Regal, a Regal "copy" (bugs my mind that someone could get a "patent" on a clamping mechanism) or something similar. Heavy machinery, does the job but is impossible to be carried around unless you can use your miles for extra luggage. I have lately moved on to a Vosseler vice for travelling and tying at home. It attaches to everything "flat and gas-tight", like a window, the foot of my lamp and so on - and it´s lightweight and super flexible. I took a bit to get used all that flexibility to be honest, but now I do not want to miss this again.
I try to limit the hook variants and use one type of grub hook and one simple dry fly hook in various sizes.
I mostly use seals fur or hare dubbing. The dubbing is stored in small plastic pouches. I cut one corner of the pouch to access the dubbing. The other storing method is to stuff the dubbing in to see through drinking straws, or in a plastic container made from greenhouse window material.
fibres from an arctic hares foot , also known as snowshoe hare. Beware of copies, the arctic hare is not a rabbit.
deer hair - I trie to get it directly from a hunter. The stuff sold in shops is softer.
materials for extended bodies
synthetic yarn like antron or polyester nylon
body materials for nymphs
hare dubbing mostly
I have a whole skin from a partridge, a few pheasant tail feathers and a big bundle of peacock herl.
I use very little genetic rooster hackle in my flies and keep it to either black or grizzly.
a hares mask is very useful and can be used for many flies. It supplies hackle, dubbing, tails & legs ... you name it
squirrel skin, mink zonkers
copper wire, tinsel
beads & lead
Tungsten beads are a good choice. Due to the high specific weight of tungsten, beads from that material can be of smaller size than other materials. Lately some new form of tungsten heads came onto the market featuring up with eyes and such. Nice to look at, but not necessary.
adhesive lead foil
I found a pouch for - believe or not - orthopaedic stockings (not mine in a shop). This bag is really „it“ - all material & tools (except the vises pedestal) has place in it. It simply is rolled together for transport.
So you can see that it does not need half a house for a fly tying kit.