Got my scale on Sunday, so I now have four 20ml single flavors mixed and steeping (used 30ml bottles for shake room):  PUR Sweet Tobacco (7%), OSDIYS Lotta Latte (10%), OSDIYS Lucky Shot (10%), and PUR Butter Mint (5%). 
Measuring by weight was quick & easy, but I really need to learn patience with that scale though... It takes many seconds for weight to register.  I was off by a few hundredths of a gram for almost everything, even though I knew it was slow when I bought it!  

  Having nothing more to do but put away the supplies afterward (no washing) was a breeze!
The percentages I used for each were numbers that seemed to work well for others, so I ran with them.  All smell good so far, so I can't wait to see what I end up with.  Any experience on any of these flavors and your percentage (SF & mixes)/aging guidelines?  I'm already contemplating mixing a couple of these together... For Science (hence the larger SFT size).  
 
I may change one thing going forward though:  I read somewhere that 100% VG was better for storing nicotine (due to the viscosity of the VG when it is cold, keeping it fresher, something, something...), so that's what I bought.   Due to the viscosity, it is much more difficult to measure out correctly for me.  What bases are your 100mg nicotine in and why?