I buy something like this:

http://wholesale.heartlandvapes.com/nicotine-18mg-gallon.html

the 50/50 blend--or buy two containers, one PG and one VG and mix as I want

and buy a couple of these for flavoring:

http://wholesale.heartlandvapes.com/flavoring/tobacco.html

and just add the flavor to the juice per instruction, and go? Thanks.

What strength do you vape at? 18mg nicotine base is kind of low and won't last too long if you're a 9+ nic level vaper.
Do you have freezer space to store the nicotine while it sits? Nicotine degrades over time due to heat, oxygen, and light. It's generally recommended that you keep a small amount of nicotine base available to mix with and the rest sits in the freezer as it's the best way to make it last.

I usually buy 18 juice, thats why I picked that out. I figured I'd end up around 15-16 with the flavor dilution. I guess I might get 24 and 18 or 15-16 and get it a bit higher, but I'll adapt to what I end up with.

Yeah, I can make room in the freezer for it. I guess I'll just mix up a few batches and freeze the rest. Do you need to store an unopened container in the freezer like that?

But other than that, there shouldn't be any problems with the plan? I just want to be sure I'm not missing anything obvious since I don't know much about making vape juice.

If you don't mind the dilution down to 15-16ish then you'll be fine with what you picked out. I have no experience with their flavors though.
As long as you have a few empty bottles you can put juice into you'll be pretty much set. Go to walmart and ask for a few of the oral medication syringes (should be free) in 1 ml and 5 ml sizes and you should have everything you need.
You can store an opened bottle of nicotine in the freezer as well. Just let it warm up first since VG gets super thick when cold. Make sure you shake it too since nicotine in VG tends to clump together and create little "hot spots" of nicotine.

I'm probably making it sound way more complicated than it is. Get free syringes from walmart, let nicotine warm up to room temp, shake the shit out of it, make juice, put nicotine back in freezer.

Thanks.

Just go to Nude Nicotine and buy their pre-blended nic liquids...many levels available and many combos of PG/VG too, then buy some flavor and off you go.

If you wanted to make it as simple as possible...bam, this is the solution.  Add flavorings, shake it up and go.

I might have to shop around for prices on pre-mixed 3mg.  I had reasons for not going this route, but those reasons are gone, and this would make mixing even easier than it already is.

Right after I kill this gallon and a half of VG.  

Well, I'll update and let you all know how it works out, hopefully I wont fuck it up too badly.

Interesting thing that happened with this-I called into that place to find out if they recommended mixing by weight or volume. It turns out the FDA has barred manufacturers or sellers of products like this from giving advice on how to use their products, they said they had to refer me to some links on the bottom of their page that went to facebook posts (that I cant get to) and a forum. I don't know if they were misinterpreting FDA rules or not, but I wouldn't be surprised if they weren't. Anyway, I guess I'll just do volume for now.

Mixing by volume is easy.   I've been at it for several years and still dispense the flavors and nicotine via syringe (volume).  I start with a 60%pg 40%vg base that I measure by weight since it's a PITA to do by volume (I mix 120ml batches of most of our favorites).  That base amount is the same for every recipe, so that makes things easy.

Download one of the popular mixing calculators, and also make sure you keep track of your recipes.  It's pretty rare that you nail a flavor the first time, so take notes about the changes you make, how those changes impact the flavor, etc.  

Good luck!

I mixed by volume for about a year. It's easy and oral syringes are free at walmart. I still have about 50 syringes still in packaging.

That being said, for extremely small batches (I do test batches of 5mls for new recipes), volume sucks. Since I got a scale, I've mixed by weight and haven't looked back.

It's quicker since I don't have to fuddle around with caps and taking out the nipples. It's cleaner since I don't have to fuddle with syringes. It may be more precise and constant since syringes can be slightly mismarked.

Volume still gets the job done but I prefer weight.

I'm only a couple weeks into making my own juice, and am doing it by weight, but I don't see myself ever going to mixing by volume.  My current flavorings are in squeeze bottles, so all I need to use is a syringe for the nicotine.  Easy peasy.

I order a liter of 6mg 100% vg and juicy peach 16oz tfa and 4 oz pomegranate tfa. I have a 4 oz dripper bottle for my peach and a 2oz dripper bottle for my pom. When I get low i grab the Nic and pour about  80-85% of the dripper bottle and put some flavoring in. Shake well and continue on.
I have been doing this for over a year. Easy peasy. I order everything from Heartland

Welp. everything seemed to go fine. I got 2 liters of 24mg PG and 1 liter of 18% VG. Making roughly 70% PG and 30% VG juice. I used volume measurements, used these numbers for 50ml

7ml flavor (flavor is PB based)
28ml PG
15ml VG

I'm completely satisfied with the juice produced by this. I went a little bit lighter than the 20% flavor percent b/c I don't want things strongly flavored.

I actually weighed the bottles after each addition, the numbers are an average of 3 different juice bottles

7ml flavor PG= 7grams
15 ml VG =19-20 grams
28 ml PG= 30 grams

So the VG is more dense per volume than the PG by about 1/4 (or 1/3? my math real bad), and VG seem to be close to a tiny bit over 1gram per ml

As far as that company goes, I have to give them kudos for taking perhaps the most care I've ever seen packing stuff. For instance, I ordered some of those glass medicine eye dropper bottles. They ship them broken down, the pipettes for the bottles had some extras, and the pipettes were packed in a tube of bubble wrap about a foot  long and 3 inches wide. As far as the products themselves, their juice seems really fresh, and I think the flavors are very good, though I'm nothing close to a connoisseur as far a juice flavor goes. The one kind of exception was the Cubano, it was pretty strong at first, but the flavor mellowed out pretty fast on it and it turned out fine.