I'd be happy if they just read my damn profile before hitting the post button LOL I know its long and boring but it tells you what I'm looking for (and when I'm looking etc) I'm more than the sum of my pink bits! . I like politeness and like to take it from there. Manners are free and do not take a great deal of effort (respect fails into that nicely) I'm not a grammar cop either. To me personally, the gist of a message is more important.
I dont expect much to be honest so I dont think there is a right or wrong way to make contact. We all have differing styles so that is often reflected in cold contacts. The odd open ended sentence would be nice, so if there is content to continue off... to see if things could progress further and grow organically. Often those one liners are hard to form a conversation that has any direction or form to spring from. That said, I'm not against the odd one liner, if has merit and direction. One of my poly partners got my attention with a knock knock joke. It broke the ice. Others have been long winded almost resume style approaches. Both have worked with me..for me its more about the content and on going "chat" than the "request or application for service" I'll ask all those important things like kinks and interests when or if it comes to it. If you read my profile you'll know the basics of my life. I want a whole person, not just when they are submissive. I want to build "more" with a person, they need to show me there is the ability for that "more" within ongoing contacts, even if it is eventually.
I do answer all messages. I ask for politeness so should be polite myself in return. I do feel for submissives that post cold contact, after contact. To never even get a "thanks, but no thanks" in return..effort should get effort in return, its a real human on the other end of the message, that has feelings too. I like to keep that in mind. Its hard to put yourself out there if you just get shot down. If your sending cold contact after cold contact and getting nothing in return....maybe look at the method your using

Maybe its your approach.
I will also add I'm over blank profiles with no details or even an age. Just being submissive isn't enough....I need a person too! Seeing more about you as person makes for further interest (I know i'm not alone as Dom/me wanting this)