William Ware Theiss or Bill Theiss was the costume designer on the original Star Trek and for the first years of Star Trek: The Next Generation. He was responsible for the iconic Starfleet uniform designs that are so often copied these days. Theiss was a three-time Oscar nominee and an Emmy winner for his work on TNG "The Big Goodbye." Theiss was famous for being able to make something from nothing. He had minuscule budgets to work with on TOS and was still able to create compelling and unforgettable designs that fans will never forget.
Theiss' contribution to Vulcan design began with the TOS episode "Amok Time" which is probably the best-remembered Vulcan-centric episode of the entire franchise. His costume designs for the Vulcan guards at Spock's koon-ut-kal-if-fee ceremony are simple, yet striking. Here is a sketch which became the basis for these costumes. 
With very few lines, Theiss was able to lay out an indelible design for the guards which was also the basis for Stonn (Lawrence Montaigne)'s costume.
Also in "Amok Time," Theiss created two beautiful costumes for the Vulcan women T'Pring (Arlene Martel) and T'Pau (Celia Lovsky). The T'Pau costume began a long tradition of including elaborate jewelry for Vulcan Masters. It is such an incredible piece that it sold for $45000.00 at the Christie's 40 Years of Star Trek auction!
Theiss' Vulcan designs also extended to Spock's parents: Amanda Grayson (Jane Wyatt) and Sarek (Mark Lenard). The ambassadorial couple visited the USS Enterprise in "Journey to Babel." Theiss crafted two militaristic jackets for Sarek and two beautifully flowing gowns for Amanda. The ones pictured below sold in a Profiles in History auction for $25000.00! 
What's most impressive about these pieces is that they look like clothes and not costumes. Often, science fiction designers will focus on finding new and interesting "looks" but in the process, forget to create something that feels like a functional item of clothing. Also, established here, is the tradition of dressing Vulcans in warm, earthy colours and metallics. This theory of design will hold (more or less entirely) throughout the next forty-plus years of Star Trek.Perhaps Theiss' most important contribution to Vulcan culture is his design for the IDIC. During the third season of TOS, Gene Roddenberry noted that fans were clamoring for Star Trek merchandise. He had Theiss design a symbol to represent the Vulcan philosophy of IDIC (Infinite Diversity in Infinite Combinations). The result was first seen in "Is There In Truth No Beauty?" and it frequently appeared in the subsequent Trek films and television series
becoming the ultimate symbol to represent the Vulcan species.
Finally, Theiss created a very memorable costume for the "Father of Vulcan Logic," Surak (Barry Atwater). Below is a design sketch for Surak's appearance in the third season episode "The Savage Curtain."
All of Theiss' Vulcan costumes manage to create a sense of otherworldly-ness while at the same time, being familiar enough to identify with. They are the clothes that one would expect a race of philosophers and logicians to wear. They evoke a sense of mystery, tradition and mysticism that pervades Vulcan culture.
William Ware Theiss passed away at the age of 61 in December 1992 but he lives on in his remarkable creations.
The Theiss designs featured here were found in The Star Trek Sketchbook by Herbert F. Solow and Yvonne Fern and in The Art of Star Trek by Judith and Garfield Reeves-Stevens. More can be seen at this wonderful Online Trek reference, Forgotten Trek