Increasing font size

[asha g]

I have asked parts of this question before, but one part is still unclear:

1) How does one increase the font size of plots - Xlabel, Ylabel and title ?

2) I have now plotted my plots without doing this, so how can I increase this 
while putting my plots into PdfLaTeX -

I know this is strictly not a Octave question, but maybe you can help.

3) Which is the psfrag package used for PdfLaTeX ? 

How do I write it so that I can increase font size ? 


eg \psfrag {Soma}{\Large{$Soma$}} does not work.

Thanks

Asha