Knowing when to replace a coil head takes a bit of experience.
And the thing that this thread has really driven home is the fact that IT'S NO BIG DEAL! You can't do it wrong!
What's the worst that can happen? Aside from it not working at all and not having a spare coil, the worst that can happen is that it tastes bad. So I can just think of it as bumming a cigarette off someone who smokes menthols or some other flavor I don't like. No big deal. I'm still going to get a hit of nicotine, even if don't like the taste and then I can simply go get my own cigarettes - or in the case of vaping, go get a new coil. No big deal.
It's the addiction that creates this stress. The "what if?" stress. That's all. It's the idea "What if it breaks or what if it doesn't work for me?" but if I - one whose surgeon had to PRESCRIBE that I be taken outdoors so I could smoke to stop me from tearing out my IVs and going home - if I can vape, ANY smoker can vape. ANY smoker can quit smoking. Just stick a pack of cigs in the fridge or freezer to ease your mind about it and get started.
Obviously, "it's subjective", LOL - there are as many ways to vape as there are people who are vaping. You can't get it wrong. If you don't like it, you adjust something. Get a different juice. Adjust the size of your hits. Close your eyes and take smaller hits if it makes you cough so you don't see how much vapor there is. If you can't inhale, don't worry about it! Take a MOUTH hit because you'll still get your nicotine via the membranes of the mouth. It is TRULY no big deal! You TRULY cannot get it wrong.
Here's what I'm going to do -
I will ALWAYS have two pens with me. Charged and juiced with something I didn't particularly like (which will not go to waste) and they will be there if I need them and I will ALWAYS have coils on hand for those pens. No matter what else I do, no matter how many tanks or batteries I collect - I will NEVER "run out" of juice or - even worse than not having a cigarette was HAVING a cigarette and no way to LIGHT it, AARRGGHH - so I will NEVER be without coils for and a functioning and charged EVOD. If I have to, I will use a solar charger or sit and charge it in my car with a 12V charger and charge incrementally, just to make sure I don't destroy a battery.
The lengths I would have gone to for a cigarette are not going to be relevant for vaping. I can vape in a bathroom stall and blow vapor into my armpit if I have to, LOL. It's liberating, in SO many ways to be free of the smoke! It's just SMOKING without the smoke and all of the damage and attention it creates!
Even if I wasn't quitting cigarettes, I would STILL keep this pen handy, juiced, charged and functioning. If I was still working, I would be sewing little pockets for it into every skirt, jacket and pair of pants I own.
I've walked out of a job because I couldn't smoke. Granted, I got hired back and special privileges, but anyone who trashes VAPING in my presence is going to get a huge dose of the militant smoker in me. And I'm a philosopher! I can crush their very soul with one short and single rant! ROFL!