Vibhor has written
In Exp system you just have to stand at spawn points and get kills but in elder scrolls (since daggerfall) practice makes one perfect
like jump too many times (say 100) and your skill will increase
Use weapons to hit monsters and your weapon skill will increase
it can be limited in stranded 2 since jumping requires stats drain so you cant jump 100 times straight
and if you increase your major skills a specific times you level up
this might sound bland and over powering but is actually fun and balancing
you can make character creation process a bit more interesting like choosing class like warrior,thief or mage
warrior will have combat related major skill,thief will have stealth and mage will have magic
well its up to you