Need advice on overclocking an MSI 750ti OC

[MixedMartyr]

I have a 750ti(specific model here), and I was wondering if it was possible to safely get any more out of it. I have a generic 500W PSU, which is enough, but the fact that the card doesn't have its own connector and gets all of its power from the board worries me a little. I do plan on getting a better power supply when I can afford it, but is it possible to get a little more performance out of the card until then?
Thanks.