This is how I handle skills in my Xuh’lan campaign. Pretty much a shameless theft from EPT and Savage Swords of Athanor.
As a general rule we assume that the PC is capable of any action that the player suggests unless the GM decides there is a compelling reason to think otherwise.
In some cases the PC will need certain skills or tools in order to perform certain actions. For example a PC who is not literate will not be able to read a document and someone lacking knowledge of super-science or who does not have the necessary equipment will not be able to repair a damaged technological artefact.
If the PC has the necessary skills and equipment and the player describe how they are used in a reasonable or clever way the action succeeds automatically. On the other hand, if the PC lacks the skills and tools or the player presents a severely flawed plan the action will fail. If the player has not given any real description of how the PC will achieve the stated goal or if his or her plan is not really convincing the GM can let the player make a saving throw to see whether the action succeeds or not.
When a player makes a saving throw the GM may allow a bonus based on attribute bonuses and other conditions, but the GM may also decree that negative modifiers are to be applied.
A not very complete list of skills:
Apothecary/Chemist: herbs, drugs, poisons, analysing chemical compounds
Hunter: tracking prey, setting traps.
Mechanic: construct, operate and repair mechanical devices
Medicine: first aid, simple surgery
Merchant: appraise, accounting
Scholar: history, philosophy, geography
Super-Science: operate and repair super-scientific devices