Jeanne's War Techniques

1)Jeanne was known to have an aggressive style in battle

Jeanne D'Arc was an aggressive military commander who always opted for offense instead of defence.  It was this attitude of hers that caused her downfall. For one she had no strategies of defence when she entered Compiegne. Compiegne being a city of defensive mentality managed to survive however Jeanne's strategy of offense caused her to be captured on the very first day of the siege.

2)Jeanne's sword : 

Little is known about Joan's sword. It had five crosses upon it and it's rust was easily removed. Apparently her voices guided her to to the church of  ST Catherine where she found the sword behind an altar. Jeanne mentions two scabbards that were given to her to hold the sword however she chose to construct one out of leather (Being practical) She also recieved two other swords, one from sir robert de Baudricourt and one from a Burgundian soldier. Her sword (the one she found at St Catherine's) was said to have a long and tapered blade but the history is blurred as to if this is accurate. Once she was caught,  she never revealed to anyone what had been the fate of this sword. Also interesting fact: She used to chase away prostiitutes w=from camps with this sword of hers.

3)Cannons:   Jeanne was known to have excelled in gunpowder warfare, that is she was extremely skilled when it came to working with the cannon. It is said that she could not only place and aim cannons but also predict an enemy artillery target.At all of her successful sieges, Jeanne always had superior firepower. The downside of being so reliant on artillery meant that when it was not there, the chances of success diminished. At her four losses: Paris, La Charité, Choisy-au-Bac, and finally Compiégne–Jeanne was outgunned.

4)Jeanne's Armor: 

She  was given a suit of "white armor" by Charles VII  White armor was a type of armor worn in the medieval period that was highly polished and when viewed it looked almost white. Jeanne wore this armor until Paris when after being wounded in the assault upon Paris she left it at the alter of Saint Denis as an offering which she later described at her trial "that is was an act of devotion, such as soldiers perform when they are wounded.

5)The theory that she was the source of morale and didn't actually fight: 

The extent of her actual military leadership is a subject of historical debate. It is believe that she merely provided morale. This type of analysis usually relies on the  her own testimony during her trial, where she stated that she preferred her standard to her sword. Though remembered as a fearless warrior and considered a heroine of the Hundred Years’ War between France and England, Jeanne apparently never really fought in battle but instead provided inspiration for those who were fighting by using her banners. She also outlined military strategies and provided diplomatic solutions.

Sources: 

http://www.history.com/news/history-lists/7-surprising-facts-about-joan-of-arc

http://musee.jeannedarc.pagesperso-orange.fr/sword.htm

http://www.maidofheaven.com/joanofarc_armor.asp

http://www.scottmanning.com/content/joan-of-arc-military-successes-and-failures/

http://www.scottmanning.com/content/joan-of-arc-cannons/

http://www.schillerinstitute.org/educ/joan_ib.html

http://historywarsweapons.com/joan-of-arc/