To prep, I usually wipe the new atomizer clean with a cloth towel, then add a drop of flavorless (or whatever e-liquid..) and let it wet burn. As someone else mentioned, it's best not to inhale the first few times- you'll be able to tell when you're getting the flavor you want.
To clean, I put it in a bit of 190 proof everclear and let is sit out overnight. The next morning I remove it and let the remaining alcohol on the atty evaporate, and try it like a new atomizer. So far I've found this method works better than a hot water bath, but I haven't tried any of the other methods yet, such as boiling. I'm in ~2 months and haven't found a reason to take one apart. The atomizers seem to hold up well, but I have had to toss a couple of LR attys.
Some people claim to have no problem with 100% VG juices (such as Boba's) but I have had zero luck with this. I might get a couple decent hits, but it usually stops wicking shortly thereafter. Mixing with another juice (CC House Blend as someone mentioned is an excellent idea!) would do the trick, and I've also read you can add a drop or two of distilled water to thin it out- but haven't tried that yet.