Well as I've posted in past few days on couple of posts, I'm going to make a shorter post of similar matter here for you, considering you're looking for offline thing more than just online.
Your ad, the amount of time you put into it, the more chances you have you'll attract potential master/mistress. So take your time and write up about yourself, where are you from, what are your hobbies, are you a student (of what), do you work (what exactly do you do then), just so people can get general idea about who you are before even contacting you.
Also include your bdsm experience so far, were you already a slave/submissive before? for how long? brief description of past relationship like that, and so on.
Can read up on my posts when I nag on other posts to how more of a proper ad is made, read through forums to see what more of a proper ad is as well... Overall if you're serious, make it look like you're serious. One line ads just scream of inexperience (Which isn't necessary a bad thing), not being serious about it (That is a bad thing), etc.