• Open a reply box
• Set your font/size/color (option: add bold or italic also)
• Hit the space bar once
• Highlight the space and hit Ctrl and C

From then on everytime you do a post, hit Ctrl and V and type away. Saves loads of time in the long run.

I also found that if you find a font that someone else has been using and want to use it on a regular basis, copy and paste a piece of that font into the reply window, highlight that before hitting the space bar and then follow the instructions above. Works great.