Howdy nutty1,
I just started DIYing myself. A few things I have found
1. Making 3 ml samples and being consistent is harder than making 5 ml samples and being consistent. Lesser amts of the overall total means there will be a bigger "percentage" error when you make an error, and you will make errors. 1 drop in a 3 ml bottle is a bigger error than 1 drop in a 5 ml bottle.
2. Making something with a 20% flavor level will, most likely, make you cringe when you try it. After my initial cringes (yes, more than one cringe) I went down to 10% and found that a number of cringes turned into, "wow, it's a lot closer and more enjoyable!" YMMV
3. If you are using pipettes instead of syringes, as a beginner, you will never reproduce what you made 5 minutes ago. My experience will definitely be different than others, but with pipettes, what ended up in a 3 or 5 ml bottle never was the same amount bottle to bottle. Once I bought syringes, all bottles were filled to the same level. Also, if you use "drops" as a measurement, first verify that 20 drops equals a ml....it won't. If you still decide to use drops, then make sure you use the same size dropper for all drop measurements. Do not use a 3 ml anything (pipettes, syringe, dropper) and then use a different size device for the next set of drops. While we are talking about that, use a lot of care with cross contamination. I clean and reuse the syringes I have. One is marked for nic, one pg and one vg, even though I thoroughly clean them between uses. Tomorrow I will still use the same one for nic, vg, pg and the others for flavors.
4. One thing that I did, and I think it was Startle who told me, while in the DIY Forums, start my mixing only a single flavor. Ya gotta get that right, because if you start mixing multiple flavors together and you never got single flavors handled, how can you expect that Wapple flavor to be right (and that's only apple and watermelon).
5. Do like they say in all the videos on DIYing ( you have watched a bunch, not just one, right?), do it without distractions, do it slowly and methodically, and write everything down cause I want the recipe to your first multi-flavor juice.
I'm using the "e juice me up" calculator. It's easy to use, but make sure you verify all your fields before you start mixing. It's easy to not change the nic level you are using, or if your nic is 100% pg or vg or a 50/50 mix. Don't forget to hit the calculator button at the bottom, stuff don't change if you don't hit the button. There is a video on line on using that calc with other handy and very useful info.
The last thing I will tell you, is get ready, you thought that vaping on its own was addicting, HA! It seems with DIYing, you will either become addicted or you will hate it, I haven't heard of many folks in the gray area between.
Good luck my friend, let us know how it goes ( it's so much freakin fun!, this hobby just gets better and better)
Big Mac