Making your own juice is alot of fun, but can be very dangerous if you don't know what your doing. Nicotine liquid is no joke so you have to be careful. Make sure you read all the DIY stickies first and ask any questions you have before you start. I use the E Juice Me Up calculator and it works really well. I recommend using syringes to add in your components so it's accurate. Some people just use dropper bottles, but I don't recommend it bc some dropper bottles give very different size drops. I have 2 different ones that look very similar and one takes 18 drops to equal 1ml and the other takes 38 drops to equal 1ml. That is a HUGE difference. I would at the very least use a syringe for adding the nicotine liquid in bc that needs to be accurate for the end result to be the mg/ml you want. In my case since those dropper bottles are SO different that could be deadly. If I was trying to make a 24mg juice and thought the dropper I was using was the one that was 38 drops for 1ml and I accidentally used the dropper bottle that was 18 drops for 1ml, but still put 38 drops, that would mean that I actually put over double the amount of nicotine than I thought I was putting in. That would mean then instead of making a 24mg juice, I actually made a juice that is over 50mg/ml, which could easily cause you to OD.
I know that prob sounded confusing, but it was just to show you how easily it would be to make a possibly deadly juice.
That's why I recommend using a syringe so you ensure your measurements are accurate. I use a syringe to measure everything so them my juice is actually what I was trying to make. The nic liquid is obviously the dangerous one and needs to be accurate, but measuring the PG, VG, and flavoring should be too. Otherwise the juice won't be the ratio you were actually trying to make. If your trying to make an 80/20 or 70/30 ratio and the measurements arnt exact, then the final product is not going to really be an 80/20 or 70/30. So that's why I would just use a syringe to measure every component so then the juice is actually the ratio and mg that you were trying to make.
Like others said a 100% VG juice will def clog cartos up quicker. Cartos and tanks work the best with 30% VG or less. I normally make my juices in 80/20 or 75/25. The Boge cartos filler is wrapped very tight and def won't take high VG juices very well. I use the Ressurector cartos from CCV, which are the Smoktech 1.7ohm XL cartos, and their filled is actually wrapped more loosely than mos other cartos and seems to take higher VG juices better. So you could get some of them if you want to use high VG juices and they should handle it alittle better than the Boges. The Ressurectors are designed to be used on 3.7V, but will still work fine on an ego, they just won't run at their full potential, but many eGo users still like them