I wud have no idea how to make my own juice.
It's easy but takes a little research effort. I just watched a video and thought, "I could do that". The start up cost is a bit but once you know what you like its smooth sailing.
Just need to aquire the components and them put them together.
VG, this is the bulk of e liquid.
PG, it's thinner than VG and is mostly used at less of a ratio.
Flavor concentrates, get the concentrates for a recipe that looks good to you, with good feedback too if possible. Lastly
nicotine if you use it. Mixing with a scale (.01 capable) is the best way to do it. I got my first scale at a head shop. You enter the recipe in a DIY calculator and it tells you how much to measure. A site Called NicRiver sells kits that include all you'll need to make your first mixes for $50 free shipping.
I know it sounds complicated. But if you're interested read about DIY a bit and see what people are talking about. Like I said, there's effort involved. There's a learning curve as well to creating. That's why I always suggest following trusted recipes.