WARNING: This solution is outdated, and since the game keeps getting updated and I don't play anymore, I wont update it.Put shortly;
For the current fastest way to level solo imo, you should follow o0ArA0o's solution - and you should also look for matriarch's bones in cemetery of the forsaken in act 1. Eventhough you do not get the bounty done, the event itself gives a decent amount of xp considering how quickly you can do it with most classes.
Note that any XP bonus from gear (including %xp bonuses from gems, sets and multiplayer) only applies to kills, the only thing that affects bounty and event xp is difficulty level and pool of reflections.
One added note to make the searching faster, is that on the list of bounties in your marked act on the world map, The Miser's Will and A miner's gold will always be on top
, so you only need to check that one.
I do not recommend looking for miser's will only, while it can be faster, it is way too unreliable imo. However, if you have some friends that are also leveling up, you can get in a party and search separately and join whoever finds it, then it is definitely the quickest way.
They have removed The Miser's Will, A miner's gold, The Matriarch's Bones and Jar of Souls from the PC version, so I assume they will remove them from xbox one too sooner or later. However, the method in the video should still work fine.
I counted 100 resets, and got 3 miser's will, so I am fairly confident that the chance of getting miser's will bounty is about 5%. Seeing as I am unlucky, that is definitely not a good method for me, but your mileage may vary, but it is unreliable at best.Alternative methods:
Note that this solution mostly applies to "softcore", and requires you to have unlocked adventure mode (done the campaign once!). For your hardcore character you should never go above normal difficulty before level 70 in my opinion, to avoid uncomfortable surprises! :p The bounties listed a little further down are still the most effective on hardcore aswell, but you have to go through the campaign there seperately to unlock hardcore adventure mode.
Edit: Just noticed that you cannot change difficulty mid-game on hardcore anyway, so just keep it on normal there.
One tip I have to help speed up the leveling somewhat, is that you can switch your difficulty anytime in-game (only 1 difficulty level up or down from what you started the game on, but on the torment levels it still helps alot).
For example: If you start up a game on torment 5, you can switch it down to torment 4 in town, start on a bounty and then right before you finish the bounty (last mob low on hp/before clicking stuff to end it), you pause and put it up to torment 6 for a big boost in bonus xp and gold!METHOD 1 (Actually killing stuff and doing bounties):
Just find the highest difficulty you can handle comfortably, and start the games one difficulty above that - then lower it to your level.
The bounties that give by far the most xp/minute are:
Act 1: Clear Khazra Den - Fields of Misery
Act 3: Clear Cryder's Outpost - The Battlefields
Act 3: Clear The Forward Barracks - The Battlefields
Act 4: Clear The Hell Rift - Hell Rift
Act 5: The Miser's Will - Westmarch Commons
NB!! For Act 3 there are a few more "clear" bounties, like clear the barracks and clear the fortified bunker etc, but those are level 2 of enormous maps, and should be avoided! :p
All bonus xp from gear (%xp, +xp per kill, red gem in helm, cain set bonus) only applies to kills, not bounty or event rewards.METHOD 2 (Faster, but might be more boring for some):
The quickest method for me was to start game on torment 5 and go down to 4, go full defensive and movement gear/spec and go to the Cemetery of the Forsaken in act 1 (ignore the bounties here, as they require killing, but the event itself doesn't). There is ALWAYS one event inside one of the defiled crypts (jar of souls or matriarch's bones), and they don't require any killing.
But to be fair I had already done it on the PC, so I recognize the layouts without going through the entire thing. I also checked for "The Miser's Will" bounty in westmarch commons in act 5 each time I reset, but it is extremely rare.
The small circling I do outside in the graveyard is to get a speed bonus and also to look for pool of reflection.
A few tips if you want to try out the cemetery farming:
1. You will die, A LOT!
2. If you are unfamiliar with the area/events, you should keep resetting games until they show up as bounties and take note of how the map layout is + get a feel for how the events work.
3. If you see a cursed chest, just run back out, because then there are never any events inside.
4. If you get the bounty to kill Digger O'Dell, you know that the event is in one of the crypts without the yellow marker (it is never in the same one as him).
5. If you get the bounty to kill the Dataminer, you should follow the yellow marker, because the event is usually in the same crypt as him.
6. For the jar of souls, just run in and click the jar, then set difficulty up to torment 6 and let them kill you a bit away from the center. Wait until there are about 8 seconds or less on the timer before ressing and running in to click again. If you have a pool of reflection you don't want to lose, you can try to teleport to town and the timer will still run (but won't show). Also, with wizard teleport, monk dashing strike and crusader steed charge you can go through the gates without opening them, and mobs cant get through.
7. For the matriarch's bones I always switched to torment 6 right before clicking the body or dress or whatever it is that finishes it.
As a last note I found it better to just switch the difficulty back down to torment 5 right before quitting the game (you don't have to teleport to town or anything), so I could just hit continue right away and start over.
Just for reference, I leveled crusader from 1-70 in about 3-4 hours using this method, and I have no experience whatsover with playing crusader. I haven't tried it with wizard or barbarian, think they might struggle more than the other classes.