Questions on How to overclock my GTX 650 Ti

Hi everyone,

I just had some basic questions about overclocking my GPU and wanted you guys to give me some advice.
Like you can see in the pictures below, what is good/bad about this overclock?, which clockspeed should I increase/decrease? etc etc.
I always overclock the memory clock more than the core clock. Is that good? Lemme know in the comments.

Before:

[IMG]http://i.imgur.com/WTRuyjS.png[/IMG]

 After: 

[IMG]http://i.imgur.com/tsXfkfn.png[/IMG]

GPU-Z:

[IMG]http://i.imgur.com/1MuIem7.png[/IMG]

 

 

With nvidia cards id be surprised if you get 50 on memory and 100 with core if it doesn't fresh your Prolly fine use a stress testing utility to make sure your stable