Unfortunately, shyness can be a major blockage to RP. If you just sit there, no one knows you're trying to initiate RP. There is a middle ground, which the mechanics of PS, whether intentionally or not, makes even easier, at least since the /introduce got taken out.
/ me looks over at XXXXX.
Where XXXXX = the name of the char you'd like to try and initiate an RP with. The nice thing about PS is this will catch their attention even better, since a line with your char's name in it shows up a different color (assuming you spelled it correctly! hehe)