Depends on your budget really but never lose focus that the basics must come first so servicing/fluids/decent tyres etc
Certainly +1 for a decent service as you dont want to be unleashing stuff if your base is not sound. My Zed was pretty much stock but first things were P3 service/once over check and uprev at Abbey, then gone for looks overs performance. So full interior retrim/carbon dipping as I spend most of the time in the car so stands to reason that my priority, then a set of Rays/spacers ,few body work bits and finally engine bay tart up. Waiting for the bank balance to recover before next mods which will be more performance related so likely HFC's then Dyno
Simple cheap mod ? - change your bulbs for LED's - instant improvement and very cheap especially interior ones