The materials of the chess-player.
The tools of a player are at least a pen, pencil or ballpoint. But the chair on which he sits is as important - just like the table, the board, the pieces and the clock of course. For a more serious competition clock, board and pieces are well defined and you can't negotiate about alternatives. The chair and the table is more free of choice but seems at least as important for the concentration, chess-experience and later memory of the game.
Let us start with the clock: my preference was always the Gardé clocks (indeed with an accent aigu, which only later became clear to me - how can a German clock be called Gardé?). Classic - and surprisingly of a very good quality for an East-German product. The white plastic Russian clocks rather had an uncomfortable touching feeling and above all looked very cheap. Then you still had those very small analogue clocks (brand?) and that was it in our club. No, Gardé was clearly the best. Good clocks also to play blitz. Soon some rings were added around the buttons to avoid blitz-players knocking the clocks with their fists. However a good player can press quite hard with one finger too. Incidents, when a button of the opponents clock literally flew in the air due to the power of pressing it, are today an individual validated part of the world-history.
Eventually the digital clocks arrived - initially there was a wide variety, but when DGT popped up (and got the support of Fide) it was finished with the "thousand flowers". Later still some other brands came (I remember KOSK used a very special type - and maybe still is) but the DGT is today still the reference. That is not really a problem as DGT is a solid clock but some habituation was necessary as how to understand when a flag was down. But for blitzplayers this evolution was great. Finally you know 100% sure that you can play 5 minutes against 3, and not that the flag is down 10 seconds too early. Also people struggling always with the clock are very pleased. I once managed to lose track of the time at my 38th move in a game played in the interclub. I made my choice - looked at the clock if I would already move and ... only 3 seconds remaining! I immediately executed the move. 3 seconds ... for 2 more moves. My opponent should've moved fast but instead he wanted to make me nervous and went for a walk. That gave me sufficient time to calculate the lines and find an answer to the 2 most plausible answers. I managed to make move 40 and win the game. Without the digital clock I would have lost the game.
Next are pieces and board - as long the board is foldable white-brown/black plastic/carton, it is fine for me to use loaded pieces. Every player knows that the knight is a problem-piece when cheap wood is used as material as it is almost impossible with a lathe to produce one piece. As it is often built by gluing 2 wooden pieces together, sooner or later they come loose. My very first set from my grandfather has that problem. This disadvantage you don't have with plastic pieces. Still the knight is a weak piece especially when the ears stand out. A second risk-element are the rooks. A crenel can break off from the piece when it is dropped off the table.
Pieces used for competition are normally loaded. Non loaded pieces are for amateurs. Special design sets can be bought in some art-shops and don't take the loading into account. Once I was given as present a set of metal pieces on wooden stands. It was not possible to play with them - the knights were completely out of balance! Yes the board was nice but such a shame were the pieces...
Sometimes we can be lucky to play on a wooden framed board, often including very nice wooden pieces. I haven't encountered such competition-conditions often (Veurne played with such set in IC but that is probably the only club in West-Flanders). If you don't often use such set then you notice this more quickly- attention which you don't spend to the game itself- you realize which pieces you have in your hands. The effect disappears after some time but the feeling of such board is important - even for amateurs.
So we already covered the board, pieces and clock. What else? Table and chair. An organizer often doesn't have much choice which ones to pick but he can vary how to set them up. How many boards on a row of tables. And that is often a difficult choice. A regular mistake is to put the boards too close to each other or the tables are just to small. Too small means no place for the paper to record the game, the pen, a drink... on the table. Too far positioned boards from each other are good to concentrate but you lose the feeling of playing together and get a chance to peek at the position next to you. It is a fine line...
The rows of tables can also be put too close to each other, especially at tournaments. If you are unlucky to be locked up, then it can be quite difficult to leave the playing-room, in a row of almost back-to-back chairs. You definitely will hit the sweaters and jackets which are laying on the backside of the chairs.
The table should have the right height. You don't want to be hanging at the bar or sitting uncomfortable on a too low chair so you need to stand up to move the pieces on the back row (especially not when being low of time). Fischer once gave the table-maker almost a heart-attack (I believe it was at the WC in 1972) when he wanted to cut off a side of the specially framed table. Some sewing was done. The most beautiful picture in this aspect must be the one of Burn against Owen (see e.g. Edward Winter's chess explorations 54). It looks impossible that both are sitting comfortable, Burn straight up in a higher chair - 20 cm it seems. And still both heads are at the same height.
You really don't want a table which is too low, so it is difficult to get the knees below (I am rather tall), or you can't cross the legs comfortably. Finally there is also the horror of a wobbling table. Nothing worse than that, especially when the effect pops up after every change of posture from you or the opponent. Then a subtle play starts of when (or when not) putting pressure. Not always carton is available and then it is a matter of finding a silent agreement.
Finally we have the chairs. In Gent I once saw somebody leaning on the 2 back-legs of a white garden-chair and immediately crashed through - don't do that. If the tables are not very strong then the chairs are often even worse. Often the classic chairs are the best to use for playing chess. Famous are the test-sessions in a WC-matches before the first game: the room is inspected, the light, the sound, the board, the table, pieces and the chair. Comfort should not dominate as this is not good for the concentration. A chair should support but not let the player fall a sleep.
The last comfort-aspect is the lightening. The worst conditions which I experienced where in open Leuven (sorry people). Not enough daylight, insufficient light intensity - some table had even their own desk-lamp (personal or supplied by the organization?). It was almost impossible to make pictures. The analyzing-room with a bar at the street-side had much better playing-conditions but probably was just too small for all the participants.
The lights are very important for players - Fischer (again he) could complain a lot about it, but his comments also improved the conditions for all other players. Too bright sunlight is to be avoided (here the advice of Ruy Lopex is still valid: turn your back to the sun), but a place close to the window is always preferred to one in the middle of the room. Daylight can't be beaten and sometimes TL-light can be quite annoying, especially if the ballast doesn't work fine and the TL is blinking. Halogeen-lights are fine but the yellow light can quickly give the impression that there is not enough clearness.
So - a player can handle a lot of bad conditions, but top performances can only happen in optimal conditions. And I didn't talk yet about sound (the ever pub-problems) the heating, the drought, the repetitions of other clubs next, above or under the playing-room...