The 2 keys to good xiaolongbao is IMO
1. very flavorfull meat/stock
2. Strong yet thin skin
Basically the thinner the skin that is still effectively able to hold in a decent amount of soup, the more skilled the maker.
As to XLB eating tips, take a small bite of the skin, slowly sip the soup, then eat the whole thing.
There is also XiaoLongBao's bigger brother, the Tang Bao
http://www.madaboutshanghai.com/imag...21/xlb_1_2.png
and its fried cousin, the shenjianbao
http://upload.wikimedia.org/wikipedia/co...ao_on_a_pan.jpg
But all three of these I wouldn't really consider Cantonese Dim Sum.