Invest in a good text editor. See the following questions:
https://stackoverflow.com/questions/100084/what-is-a-good-gui-text-editor-for-the-mac
Mac text/code editor
And by 'invest' I mean both money and/or learning time.
XCode is a good enough editor for Objective-C, but I wouldn't use it as my primary editor for everything.
(MacVim is my choice)
