Higher VG is definitely going to reduce the harshness, but as others have noted, if you just add more VG then you're juice will be weaker in nic and flavor - if available in a higher VG alternative then you could mix the two, with the same nicotine level; although I personlly have gone down the DIY route; I usually have up to three flavors on the go for different times/moods, and I decide the strength of not just the nicotine, but also the flavor - some flavors I like very weak, whilst others I like "in your face". Each to his/her own.