well, I know this maybe one of the least helpful suggestions, but you can try to please other faction's lords to like you more by helping them in battles, etc. after doing some of that, your honor and rep might increase.

You can earn some money and hire mercs and then take on small bands of lords or small groups of soldiers like caravans/army of a lord with more than 20 prisoners but with a large number of wounded soldiers.that way you get some renown and some extra troops at the same time. try being around caerfernon (dont remember the spelling) of the principality of the wales, that's where england and the welsh always have battles.

You can help either faction and prey on the armies that have gotten weak with tonnes of wounded soldiers and prisoners.

引用自 Parrhasus：

When i play as a bandit i only lose honor and reputation when i am attacking another lord. I don t gain any renown. There is no difference playing as adventurer or as a bandit ...
do u have any clue ?

You can hire other bandits.