Hi Vtwin, and welcome!
This is a pretty personal preference. There is no "best", as everyone is different. You will likely get personal preferences here, but it seems like a common ratio is 65:35 PG:VG, or there abouts. But only you can decide if this popular ratio is something you like.
What is
my preference? I don't like PG at all, don't like the taste of it itself (slightly flowery to me) and it dries me out too much. I make my own juices with VG, VG-nic unflavored, 5-10% flavoring, and distilled water to thin it. I like both the flavor and vapor of my DIYs very much, and they have plenty of TH to me.
Others like all-PG, or 80:20 PG:VG, or almost any other combo you can think of. My suggestion is to simply try a range of
juice compositions, a little of several, and see where you gravitate to. Warning: what you like with the first hit might not be what you like in a weeks time of
vaping. Tastes change, and negative effects can take time to develop, so be patient. Most here take a couple months, at least, to settle on what they like to vape all the time. Certainly did me, and then some. The key is to have fun, spend a little on yourself, and enjoy. If a juice is absolutely not good for you (why I recommend small amounts initially, as you can always buy more...or make more if you DIY), you can trade it in the classifieds here.
Have fun, good luck, and happy
vaping!