since u are an offical clan its kind of hard to get people via. forums.
only possible way i imagine is that u help people out in the beginner forums etc. and got in the signature something like "deckers, now recruiting! beginner friendly!" so that the people which come to you can get help from the clan members if they have questions etc.
the ohter possibility is to go ingame and search for people there, from what i noticed i get quite often asked if geru still needs member, im sure that is like the same for every clan. just make your clan a name, you could host a deckers betting server, a few tourneys just so that the people get known to the name.
the only problem with most of the new recruited people (which dont play the game that long.) is that they probably are quite forum inactive and willl probably end up stop playing the game because it gets boring due the high learning curve. maybe just 1 out of 10 will stay a while. so its just quite hard to make a good (offical anytime) clan with active members which are recruited as new players.