Surf internet for a font you want for example I found cool font for me at http://www.dafont.com/punksnotdead.font click download button.
Font downloaded in zip file Please Show Me Love Demo.zip unzip it and select font with extension .ttf
Connect phone to your PC with USB cable and mount it so that you can copy font from PC to your Phone's SD card
in your phone the way you mount SD card to PC may differ a bit but I think you got the point.
Navigate to the Picsin/Fonts folder in your phone's SD card and copy downloaded font there.
Now we need to safely remove removable drive from PC and switch usage mode of USB in phone from Disk drive to Charge only.
Start editing pic go to choose Font and navigate to My Fonts section there you'll see the font you downloaded
Of course you can spice up the font with colors
Here is the list of nice fonts you can download for PicsIn
http://www.dafont.com/graffiti-treat.font
Share cool font links by commenting to this Post.
Happy font usage hope it helps!