I moved from clearos to novas because i got tired of the leaking then i got tired of the muted taste with my novas. Follow the link at the bottom of Baditude's post to see what they look like. They are really so much easier to use once you get priming the carto down. I followed his blog instructions the first time & I've had very little problems. The flavor & vapor is amazing on the Provari!!
The first and last part of this article deals with cartomizers and cartotanks, respectively:
http://www.e-cigarette-forum.com/forum/blogs/baditude/3230-1-proper-terminology-carto-tank-what-primer-juice-delivery-attachments.html
How to set up a cartotank:
http://www.e-cigarette-forum.com/forum/blogs/baditude/3710-5-cartomizer-tank-setup.html
When using a carto solo (not in a tank), prepare it the same as the second article describes for prefilling the carto for use in a tank. Since you can not monitor the juice level, don't be afraid to "top off" the carto with more juice from time to time to keep the filler material moist.
The filler will always appear to look dry from the top after a few vapes on the carto; this is normal and not indicative of how much juice is in the bottom of the cartomizer, where the heating coil is. When you first notice a little bit of burnt taste, top off the carto to prevent burning the filler. Once you burn the filler, you will never get the burnt taste out of a carto and it will be ruined.
After some experience, you will "know" about when the carto will need topping off with more liquid.
You should be able to refill the carto multiple times. Once the draw becomes too tight or the flavor becomes muted and not improve with additional top offs, it is time to replace the carto. It's finished.
Diagram of a cartomizer's inner parts (click image to enlarge).