No; it only becomes lame if you keep trying again and AGAIN without getting the hint that I don't have any interest in being your boyfriend.
Also, if you're initiating the conversation on some topic, at least be able to carry on the conversation. Don't expect to start something with me, and then want me to facilitate everything from that point onward.
I have no absolute favorite way to be approached. Just do so in a way that captures my attention; you have to be interesting for me to WANT to talk with you.
Girls don't need an excuse. Walk up to him and say "Hi, I'm ____" and 95% of guys will respond positively unless you're very, very unsightly. There's no real way that guys like to be approached because being approached AT ALL is a treat for most guys.