Money more often than not came from taxes, for example: a landowner would build a mill and then charge people who wanted to use it. The very word "Robber Baron" comes from landowners in medieval germany extracting absurd and unreasonable taxes.

In medieval Lombardy, roads and bridges had to be maintained to a certain standard by the owner of the land they passed through, and in exchange the landowner could extract tolls from travelers. They could be subject to restrictions though, for example in medieval Catalonia landowners could not extract tolls from travelers bearing goods destined for the market in Barcelona.

In many places, like medieval England and Italy, many farmers were in fact renters; and landowners could extract rent either in monetary payment or the form of a portion of the crop (sharecropping). Further, taxes like tithes (one-tenth of a tenant's crop) or mezzadria (whereby a tenant had to work on the landowner's personal land or household on certain days of the week) meant that landowners could enjoy goods and services without paying for them, allowing them devote more of their time and income, however modest, to leisure. Different lords had different income levels, even in nearby places during the same time period, but for the most part they enjoyed a higher standard of living.

This is a very generic overview, is there any time period or place you're specifically interested in?