You're not going to get much since the SC is already clocked to the hilt.  In my experience, you'll gain maybe 2-3% performance, but more heat and potential instability.
 
That said, bdary listed the basics if you want to give it a shot.  For a baseline, I can get mine to around only +50 on core/+70 on mem (says in Precision I'm running at boost around 1250mhz/3572mhz in games) stable.

A couple more recommendations (I have a GTX 770 SC that I'm trying to squeeze a little more life out of it till I go buy a 1080 Ti).
 
1) Benchmark first w/o overclock, so you know what gains you may be able to get out of OC settings.  I would do both Valley and Heaven, for your 780 Ti.  
 
2) Then before you begin tweaking core clock or memory, recommend you de-linking power & temp target, max the power target, max the temp target, and set priority to temp target.  This will help you to be able to access and explore what power and thermal overhead/limit your card may have.
 
3) Also, up the voltage target to max.  This will allow you to explore the voltage overhead/limit you have.
 
4) Since you're going for performance, set an aggressive fan profile so the fans get ahead of the heat to keep your from hitting thermal limit early (and throttling back power/voltage).
 
5) Now you can start testing GPU clock offset +13 at a time and benchmark till you find the stability limit (locks up, artifacts, etc.).  Then back down last stable GPU offset.
 
6) Then you can start playing with Mem clock offset +50 at a time ... follow the same pattern.  Press till you hit stability limit, then back off.
 
7) Once you've settled, then tweak max voltage (down) till to ensure you have adequate voltage for stability but balance out hitting voltage limit.
 
Some trial & error, testing, and benchmarking, and there you go.  How much your card will OC will depend upon the card (e.g. the "silicon lottery" of your GPU).  Worth noting that your card already comes with factory overclock built in, so you're tweaking to try to get a little extra on top if it's available.
 
Every card is different, but I've been able to squeeze an extra 2-5% FPS, depending upon the benchmark or game.  Only able to get +26 GPU offset (for 1267MHz stable), +350 mem offset (for 3855MHz stable), since the stock OC was already at 1228 MHz stable (from 1111MHz base).
 
Good luck!