The Fastest Way to Paragon 300 in Season 14
Everyone knows the most popular way to level from the start is to rip Helltides, and now with War Plans, that can really accelerate your leveling.
But what about getting to Paragon 300 the fastest? Well, actually... it's still Helltides. Especially thanks to Season 14's new mechanic: Ruptures, Ruptures, and more Ruptures!
Here's the trick: don't just pop into a single Rupture and go for it. That's not enough! What you want to do is find three Ruptures close together, ideally in a little triangle shape, and start all three at once. That endless flow of demons is a sure way to rack up experience fast, and it keeps your threat level constantly popping off, which spawns even more to kill.

If you see Soul Eater Goblins while you're in a Rupture, take them out quickly when they're close by to open up another Rupture. Things can get a little crazy, and that's exactly what you want!
Pair all of this with the Writhe and Rot node on your Helltide War Plan tree (straight down the middle), which makes Hellwyrms always spew Maggots, and the experience will go flying.

And remember to always keep pushing up to higher Torments, since that increases your experience gain. Just make sure you can kill the stronger content at a good pace first, or else moving up will actually slow your experience down. If you're not strong enough yet, upgrade your gear (new pieces, Masterworking, and so on) and then try again!
If you have questions, come by my Twitch stream at twitch.tv/hellomischa