This very simple step will stop most rust from forming. Its also important to note that finger prints can cause carbon steel to rust. Every so often put a coat of your favorite oil on the knife. It is especially important that if you use your knife in food prep that you use a food safe oil like mineral oil.
Lastly, over time you may notice your blade changing color. This is a natural process during which the steel gains a patina from normal use and age.
A patina not only adds character to your knife but helps protect your carbon steel from rust which might cause pits. Many people find a satisfaction in watching how their patina develops over time while others "force" a patina in order to gain a more uniform coloration. Of course for those that like to keep their knife looking new a patina can be easily polished off. Handmade / forged / gaucho knife / gaucho knives / criollo knife / recycled steel / machete / bowie knife / carbon steel / brazilian knife / deer antler / brazilian wood / bull horn / rosewood / cedar / blacksmith / 1070 steel / 5160 steel / spring car / plow agricultural / leather sheath / sugar cane machete / dagger / fulltang / south america / rio grande do sul / solingen / sheffield / german blade / railroad screw spike / spring jeep / rasp steel / vintage knife / nicholson / trowel steel / recycled / brute de forge / argentina / friction pocket knife / solingen / chef knife / rustic knife / blue steel / stone sharpened / jacaranda / reforged /.