if you are planning on building coils and using them without checking ohms you really should research more....it's NOT safe
a dual coil build with give you lower resistance usually and your Ego isn't meant for that
putting a coil to your face not knowing what it is, is something I would never do
i agree, you must know how to at least use a multimeter, or one of those cool voltage ohms meters for ecigs. multimeter is 7$ harbor Freight and i got that recommendation from my Mechatronics Professor, but the multi meters are kinda tricky, you have to remember to text the resistance of your test leads and subtract that from the ohms you read on the atty. the voltage/ohms i think do that step for you.
Otherwise, my recommendation in addition to the one i Quoted, is to get a mech mod for RDA's and Learn as much as possible about battery safety.
I believe there is a place in this forum with that exact information in the Beginners subforum. it has links to other cites with more information than you could believe.
im not saying learn everything. just learn enough about safety and using ohms law before making a pretty nasty mistake.
and remember, RDA's are a learning curve. they take some tweaking to make them work most of the time.
i would also recommend if you do get a mech mod, to get a battery fuse as well.
Best of luck