Like the title says, what would be the best case scenario for the Qing Dynasty in the 19th century?
China under the times of Early Qing were at the most powerful at their zenith under Kangxi, Yongzheng and Qianlong. After Qianlong, Qing China is no longer the great empire it once used to be and stagnated into a weak dragon at the mercies of Colonial powers in OTL like the Opium Wars and Boxer Rebellion.
What could be a better way for Qing Dynasty to avoid the worst-offs it suffered in 19th Century OTL?