lmao, didn't 50 make a song about you called "wangster"? Seriously though, I sit most of the time I make beats because I'm usually doing other things within the program that requires me to sit as I'm making them but to really get into your beat, standing is better imo. You can use your whole body while you're in that groove vs just being able to bop your head while sitting in a chair.
On that note, I'm surprised you asked that question because I thought you needed to know HOW to make a beat first! =)