If your out of ideas or want more experience why not look into OOP (Object Orientated Programming) and look into making some reusable code, eventually making a code library for yourself.
Common Ones for this are
File/Directories
Databases
Arrays/Stacks
XML
Theres a few of course there is Pear which is basically one big library of classes however only use if need be, or even to get an idea on how others do such things.