Progressing from T1 to T4

There’s only one variant for progressing from T1 to T4 because in Diablo 4 you can obtain all the best gear even in T1 — it’s just rarer. You can usually speed-farm T4 with basic Ancestral gear, even if you only have one Greater Affix.
Most of your damage comes from Paragon Points and Legendary Aspects. Unlocking the Legendary Nodes on your Paragon Board will give a huge power spike..

The first thing you want to do is get the required items to start the build. At this point, you’re probably still using your 1–60 leveling setup.
Farm boss materials in Helltides or the Undercity with Titan Tributes, then kill T1 bosses to obtain the required Unique item. Once you get it, switch to the T1–T4 build variant.
Once you have everything needed to get started, it's time to farm Paragon XP. Paragon farming is very efficient at this stage. Unlocking Legendary Nodes provides a huge power spike, each one giving roughly 60% increased damage.
A good way to farm XP is by running Helltides to collect boss materials or Bloodstained Hordes (best way for XP farming by far!) if you can, The Butcher gives insane amount of XP! Then kill Tormented Bosses on a difficulty you can clear comfortably. This gives a good amount of XP and rewards you with Unique items that you can use or sell if you trade.
Running The Pit is also a great way to gain levels and Paragon XP early on. It will also allow you to level up your Glyphs, which provide another strong power spike when they reach level 15 and level 46. The goal is to clear Pit tiers in about 2–3 minutes, which allows you to level your Glyphs with a 70% success chance. Eventually you will hit a wall. When that happens, go back to farming Tormented Bosses and Infernal Hordes. By repeating this loop, you will steadily upgrade your Glyphs, Paragon level, and gear.
You can also Temper and Masterwork your gear if you need an extra power boost. At this stage, don’t worry about perfect rolls — focus on steady progression. Infernal Hordes, the Undercity runs Tribute of Refinement, and Treasure Breach Nightmare Dungeons are great ways to farm Obducite for Masterworking.
Finally, start comparing your gear to the final build setup or an endgame version. This will help you identify which Greater Affixes (GAs) you should target while continuing to optimize your build.
Tip: Spend your Fresh Meat in Gea Kul for a strong chance at good gear.