I am also a great proponent of mez-pulling, even on camps where lull is a perfectly suitable alternative.
For me, I think I stopped using lull for primary splits when I started doing hard ldons; it was just waay too unreliable. Pre-planning your pulls and turning them into a managable 2 or 3 I found much more acceptable, and I guess I carried on doing it ever since.
Another important thing that people often forget to mention, or just plain dont know, is that an assisting mob will not make an assist call of its own. This, combined with mez, allows you to pull off some amazing pulls and allows you to split camps nicely. You are still gonna use fade if you want singles, but with judicious planning you reduce the number of fades by a fairly large amount.
I think one of the best things that happened for me, pulling-wise, was when I was no longer able to reliably use lull on a pull. Lull I consider a crutch for pulling; too many people rely so heavily on it, that when it no longer works they don't have the tools to be able to deal with the situation.
Practice mez pulling; practice toggle-mezzing adds(11,22,33, switch target,(5) mez, toggle npcs,(5) stopmez, 11, 22... etc); if you have an unlullable add (but in charm range), use it for bonus group dps; make use of the likes of highsun for reverse splitting mobs (this invariably uses a fade a split though).
Generally, have fun though. Don't think of not being able to use lull in a camp, but think of it as having an opportunity to play around with lots of other cool stuff we can do.