I went from doing 3 dozen past lives over the course of years, to a dozen in a couple months. Here are some specific things that changed:
-started using the xp elixirs I’d been saving
-took advantage of the Halloween event to get very fast xp in epic levels for a few of these lives
-I have a bunch of AC from epic past lives, reaper points, and a bunch of damage-based past lives, so my character is generally strong
-I play builds that I enjoy and have been carefully planned on DDOBuilder (it’s a fun tool, check it out)
-and the biggest, biggest change: I don’t delay when it comes time to click the “reincarnate” button. You want to reincarnate? Don’t wait several weeks: take the leap! Oh, and the real answer:
-inventory organization. No literally. No seriously.
Some incorrect things from this thread:
-“fighter past lives give you attack and damage.” They actually give attack and +tactics DCs. (Monk lives and Dragonlord lives will give you damage- just check the Wikipedia to make sure)
-iconic lives will give you a heroic and an epic life feat. Nope. They’ll give you a heroic and an iconic life feat.
-getting +2 intelligence from certain racial PLs will give you additional skill points going forward. Unfortunately, not true
-you should farm 3x Druid lives, so your hirelings are stronger. This is the worst advice I’ve ever seen to give to a new player

jk but. Wow, no don’t worry about grinding 3 Druid PLs so your cleric hireling lasts a few more seconds standing in a pool of acid (unless you love Druid). Focus on builds you enjoy and past lives that help *you* succeed
Some correct stuff from this thread:
-don’t burnout. play what you like while working towards long-term goals
-check the Wikipedia for all the past life benefits, and pick the ones that matter most for what you are trying to do
-epic PLs are very impactful
Not mentioned:
-xp tomes. There’s one for heroic and one for epic. Normally not necessary on a first life (or first few lives, now that it takes a while for the increased xp requirement to kick in). But it’s worth looking up so you’re aware of these, as the xp bonus is gigantic and ultimately a must-have.
-xp elixirs. I used to save these “for later,” but no, just drink them (feel free to put a LITTLE thought into it). You don’t want to finish 10 past lives and realize it could have happened with dozens of hours less grind just by using your resources
And finally, some clarification just in case things are confusing:
You can get a heroic past life OR racial past life feat by reincarnating at level 20 or above. One or the other- you choose when you reincarnate.
You can reincarnate at level 20, or randomly do it at level 24 (you’d have wasted some time grinding epic experience).
You can even do it at level 30, but if you make it that far, just remember to do an EPIC REINCARNATION FIRST. This will grant you an epic past life feat and bring you back to level 20, at which point you can reincarnate back to level 1.
If you play as an Iconic, you have to go to level 30 before you can reincarnate. You will receive both an iconic past life feat and a heroic past life feat. You will not have the opportunity to get a racial or epic past life that life.