It s certainly possible - the only trouble, is that say your tobacco e-liquid was mixed at 12mg. If you add 1mg of strawberry to that, it lowers the nicotine level a tad.
Best bet is to buy unflavoured nicotine base and add one shot concentrates, pg and vg into it.
eg:
View attachment 838517
I’m trying to put myself in the shoes of folks who have never mixed. I think adding flavors to unflavored juice, most would find easy enough, and the slight drop in nic level wouldn’t be too big a concern. But also it would be an easy step toward diy
Some would find the former good enough and just keep doing it, but for others it would probably give them the confidence to attempt taking the next step.
It seems the attitude of non mixers has changed from *I like store bought* to *home made juice probably isn’t any good* and now there’s a worry about not being able to store enough commercial juice to weather the storm.
A lot of them still seem at a loss how and where to start. I wanted to start a thread to make it easy but I can’t seem to keep the word count low enough to not confuse them further.