I have the impression their problem was more one of commanders and organization than the troops.
The Austrians performed poorly during the First Coalition against France, but so did the rest of Europe.
During the Second coalition, Austrian armies performed reasonably in Germany and in Italy a combined Austro-Russian Army under Suvorov cleaned house in the Po valley.
In the later wars against the French Empire, the French initially could muster more troops and were able to coordinate their separate army corps for strategic movements that managed to defeat the Austrians time and again.
Still, Archduke Charles was a competent general and made Napoleon work hard for his victories (Battle of Wagram). At the end of the Napoleonic Wars, Austrian armies had been reformed and reorganized in the crucible of defeat (like the Prussians) and preformed admirably during the Sixth Coalition.
The main advantage of the French initially was the levee en masse, which provided them with a large number of motivated troops, their use of the corps system and a large number of competent corps commanders that were promoted only on the basis of their competence.
When the Austrians were blessed with excellent commanders as Charles of Suvorov, they were quite able of defeating the French, but these were not always available. The Austrian commanders were mainly assigned on the basis of their titles and that was a sub-optimal way to run an army.
So:
- better leaders (based on competence, not amount of blue blood) [this is difficult in the Austrian society as it was then]
- introduction of a division/corps system, instead of the regiment system that became unwieldy with the ever increasing army sizes of the time [doable]
- troops that are willing to fight for their homes (German nationalism started in the Napoleonic Wars, so no real change here) [happens anyway if French troops start raping and pillaging their way through Germany]