As part of my research, I am looking into specific construction techniques used by Florentine tailors. For in formation on layers of clothing, try Dressing from the Inisde Out. (updated 2006) and Putting on Clothes. (updated 2006).

The tailor of the Medici court,during Eleanora's time was Mastro Agostino. (La Moda a Firenze p26)

This is mainly in the areas of : 

• styles, 
• materials, 
• patterns, 
• sewing stitches used, 
• actual  construction methods used.

Styles:
Eleanora (1538-1562) had a uniform for official portraits but according to written documents and a few frescoes, wore more contemporary Florentine dress on a daily basis.
More on this later...

Materials:
This article was written in 2004, updated in 2005, and is in the process of being updated.

Patterns:
These are based on the two extant dresses, one being Eleanora d'Toledo's burial dress, and another from Pisa (assumed to be Eleanora's). There is discussion on these found in La Moda a Firenze and Patterns of Fashion. Juan Alcega's Tailor's Book also provides contemporary patterns for various outfits. A two part article is being published in Cockatrice.

Eleanora Skirt pattern based on Alcega.

Sewing techniques: stitches used
This is one area in which research is very slow and difficult to pinpoint specifically to the time and region. Assumptions can be made based on contemporary stitches used and well-established tailoring methods.

A very good summary of documented and published stitches used in Florence can by found at the Sewing Stitches Used in Medieval Clothing website.
This site quotes examples of running stitch specifically used in Florentine clothing - 

• 1562 Florence, Italy Suit of Cosimo I de’Medici. 
• Raw edge of silk on panes on trunkhose turned under and held by running stitches in 2-ply silk Arnold, Patterns, pp. 53-54. 
• Stab stitch 1562 Florence, Italy Suit of Cosimo I de’Medici. 
• Row of stab stitches down center front about 1.5mm (1/16") from edge Arnold, Patterns, pp. 53-54. 

La Moda a Firenze shows close up of extant items which appear to have the following:

Construction Methods:

• Stiffening of imbusto.
• stiffening the hem
• edging the imbusto and skirt hem
• lining

Glossary
imbusto: bodice
baragoni: sleeves
camicia: chemise
faldaglia: skirts
convercie: shoulder cape/hankerchief
gorgiere (e colletti) : partlets

Bibliography:

• Alcega, Juan.The Tailor's Pattern Book, 1589 Facimile, Ruth Bean, Carlton, Bedford, 1979.
• Arnold, Janet Patterns of Fashion, MacMillan, London, 1985. ISBN: 0-333-38284-6 
• Arnold Janet, Queen Elizabeth's Wardrobe Unlock'd, Maney, Leeds, 1988, ISBN:0-901286-20-6
• Kovesi Killerby, Catherine, Sumptuary Law in Italy 1200-1500, Oxford University Press. NY. 2002. ISBN:0-19-924793-5
• Crowfoot E, Pritchard F & Staniland K, Textiles and Clothing 1150-1450, Boydell Press, Woodridge, 2001 (ed) ISBN: 0-85115-840-4
• Frick, Carole Collier. Dressing Renaissance Florence.: Families Fortunes & Clothing. John Hopkins University Press. Baltimore. 2002. ISBN: 0-8018-6939-0
• Orsi Landini, Roberta & Niccoli, Bruna. La Moda a Fioenze 1540-1580. Pagliai Polistampa, Firenze, 2005. ISBN: 88-8304-867-9
• Ricci, Elisa. Old Italian Lace Volume 1. William Heinemann, London. 1913 available on line at: http://www.cs.arizona.edu/patterns/weaving/books.html
• Veccellio, Cesare. Vecellio's renaissance Costume Book. Dover Publications. NY. 1977. ISBN: 0 48623441X
• Willet, C. & Cunnington, Phillis, A History of Underclothes, Dover Publications, NY, 1992, ISBN: 0-486-27124-2
  
  Web Sites:
• Medici Archive Project: www.medici.org/  (1/06)
• Metopolitan Museum of New York. http://www.metmuseum.org/
• V&A Museum website: http://images.vam.ac.uk  (May, 2004)
• Bath Museum of Costume: http://www.museumofcostume.co.uk/ http://www.museumofcostume.co.uk/index.cfm?fuseAction=SM.nav&UUID=
  013DFA14-32A6-4A33-B3CDA4E8E00C9D49)
• Web Gallery: Medici portraits by Bronzino. http://www.kfki.hu/~/arthp/html/b/bronzino/1/index.html
• Archeological Sewing by Heather Rose Jones (2001) http://heatherrosejones.com/archaeologicalsewing/index.html (new address: 8/06)
• Sewing Stitches Used in Medieval Clothing: http://www.personal.utulsa.edu/~marc-carlson/cloth/stitches.htm
• Archive of Stitches from Extant Textiles. www.bayrose.org
• BayRose. (website by Savinra de la Bere.) http://www.bayrose.org/needlework/Shading-1.pdf
• "How much yardage is enough" Susan Reed, 1994. http://patriot.net/~nachtanz/SReed/fabuse.html
• Suggested Yardages for Elizabethan Garments by Drae Leed. http://costume.dm.net/yardages.html# (29/5/03)
• "How much yardage is enough" Susan Reed, 1994. http://patriot.net/~nachtanz/SReed/fabuse.html
• Festive Attyre: http://www.festiveattyre.com/research/secondflor/portfolio.html

Information provided by caitlin_oduibhir, who has seen the Metropolitan Museum's extant drawers first hand.(thanks).