search the forums to start. There are literally hundreds of threads that address this topic. You also need to provide way more information than that. Is your overall GPA low? do you have a rising trend? Are you a US/Canadian citizen? Where do plan on applying? What is your MCAT/GAMSAT/UKCAT?
example: if you are US/Canadian citizen and your "low" GPA = >3.0 < 3.5 with a significant rising trend towards your upper years, people might suggest you take more upper division undergraduate classes to improve your application.
example: you have a 3.0 GPA but a 35+ MCAT, people would probably suggest what I said above as well
example: you have an overall low (<3.2) GPA but your last two years of undergrad were high (>3.5/3.6) and your MCAT was average (28-30-ish) then apply to Australian schools where your upper years would play to your favour.
No one can help you without more information than what you have provided.
Cheers