depends on your taste.. some basic good tips are, change headlight install Xanadu headlamp with HID/LED and install a good safe-guard.. not the one available but custom made on the tone of CD200 safeguard. Install good horn, install a good pair of fog lights for looks and comfort on highways on safe guard. Donot remove the side mirrors and if you dont have a helmet, buy a good quality, preferably studds. Get a Helmet lock also and if your GS is new model then please change the indicators, the new ones look ugly IMO. Change rear tyre to 100-90/18 and change the rear RIM to Delux 125 RIM. Spokes of GS rims will be used on delux rim. that's it for now. Oh and get a irridium tip plug is you want.