I'm not sure what type of equipment you are using (and I probably know nothing about your particular equipment either =D), but I have found that aside from blowing out the atomizer, and cleaning the
threads, that unscrewing the atomizer slightly can improve the draw. On my Provari, there are vent holes on the female
threads as well as the male atomizer
threads, and when they are matched up (by slightly unscrewing the atomizer) the draw is almost too airy for my preferences (but certainly allows for a better draw if it seems gunked up).
I never thought to try this on my eGo, it might have solved some of my problems. Try giving it a tiny turn (not too loose) so that it is slightly less snug than you would normally use it and see if that at least rules out a symptom of the bad draws and gunkiness.
Other than an old/dying atomizer/battery, I can't think of anything else that would cause this as I have been dripping malty and malty toffee with no problems on several types of atomizers. They are definitely thicker than most juices (regular malty especially), but never thick enough to cause me problems (never used cartos, not sure how well they wick).