Hello. My first post here. I am fairly new to vaping (two months, having quit a 30-year cigarette habit) and have a Halo Reactor box mod (basically an istick50), and the manufacturer says that for best results, use a different atomizer for each different e-liquid, so that the flavor comes through without carry-over from a previous flavor, which makes sense on the surface (not to mention profit for the manufacturer). The thing is, I make my own e-liquid, and the flavor combinations are endless, so using a different atomizer for each conceivable recipe is obviously not feasible - I’d have to dedicate a whole dresser drawer to nothing but coil heads. What I’ve decided to do, as a compromise, is to dedicate one atomizer for all sweet flavors, one for all fruit flavors, one for all tobacco flavors, and one for all mint flavors (whatever I decide is the dominant flavor). If my strawberry cheesecake liquid tastes a little like banana cream pie from the previous recipe for a few vapes, I don’t care. Of course that also makes it hard to fine-tune a recipe if the flavor is altered by the flavor of a previous recipe. I was just wondering how other people approach this issue. Thanks!
Just wash it and rewick (rebuild if necessary) or replace the coil head 
First off, welcome and congrats on quitting smoking!! That’s awesome.
Secondly, I think that is ridiculous and just a way for them to make more money trying to buy more stuff.
I don’t dedicate anything for anything. Everything goes in my world. I’ve found that residual flavors really don’t last that long and the only time I care about it is when I’m testing. So I do have a velocity wicked with hemp that I use for that. Hemp is great at clearing old flavors out quickly. Usually after about 10 drops or so, the old flavor is gone and the new one comes through perfectly.
If you want to dedicate attys or tanks to specific things, that’s up to you, but if you don’t want to be bothered by the hassle I wouldn’t sweat it. 
Thanks! Basically my take on it is that I’m only making e-liquid for myself, so as long as it tastes alright to me, that’s good enough. I’m not aiming for three Michelin stars as a vaping chef, nor am I trying to win “Iron Vaper” . The reason I keep separate atomizers for different _categories _ of e-liquid is that I don’t want, for example, my banana split tasting like Carolina tobacco. I appreciate the warm welcome.
I do use two atomisers. One for fruity menthol flavours and one for custardy type ones. To be fair the previous flavour goes away in most cases after you change it. You can wash it and change coil and it as good as new.
I’d get a dripper if I were you. They can be super cheap (like $10 or even less). Once you learn how to make coils (its easy), all you have to do is rewick the coil between juices. Also, flavor is usually better with a dripper, so you’ll get a more accurate picture of what the juices taste like.
Unfortunately I have not stepped into the world of drippers and rebuilding. Soon I hope (tax refund coming soon).
For the longest time I had two tanks (now 4). I used to use one for testing and the other classified as the adv tank. Typically when I switch liquids I wipe out as much juice with a tissue. Then bam, just add the new juice. The first 3-5 pulls you get the old flavor, the next 2-4 I get the mixed flavor between the two (sometimes it’s good and sometime not), after that it is all the new flavor. Sure, there may be a touch of the old flavor but by the time your done with 3-4mls of you test you have a good answer on the flavor profile and the old flavor is not there imo.
I only switch the coils when there is a loss of flavor.
Ok… Well don’t get too crazy with multiple coils and atomizers… Doesn’t sound like you are…YET 
. Def look into a dripper at some point though because you be glad you did. Even if you weren’t mixing, they’re very nice to have. For $15 to $20 you’d be able to find a dripper with enough wire and cotton to last quite a while.