No More Cubes is a tough challenge to complete, and as such you need to prepare for it. The following is what is recommended you have before jumping into a NMC run:

• Auto Attack and Auto Next (the latter coming from the Only White Cube Challenge)
  
• As many Color Cube Discount nodes selected in the Prestige Tree as possible. Preferably at least the ones in the first four trees, which would get you a 55% discount, but getting the one in Tier 5 to bump it up to 68% can help wonders.
  
• As many (Color) Cube nodes as possible
  
• The Power of Cube node
  
• The Buyer Helper, levelled up so that it provides the maximum 50% Base Buyer Discount
  
• As many Bonus Multiplier, Bonus Bonus Multiplier, Attack and Enemy HP nodes as possible
  
• Completions of the Titanium Cube and Broken Meter challenges will also help out
  
• Finally, a bit of luck can go a long way

When you start your first No More Cubes run, you'll start with exactly 10k Cubes in which you will need to spend carefully. But do NOT buy upgrades from the Tick Speed shop directly. Nor should you buy the Blue Cube just yet. Instead, equip your Buyer Helper, and let them buy up all the Tick Speeds for the White Cube Meter.

Then, and only then, should you buy the Blue Cube meter and let the Buyer Helper buy as many Tick Speed Upgrades as possible for it. You can, if you want, buy 1 or 2% of the White Cube Multiplier if you want to trade in a bit of Blue Cube Tick Speed for a boost to how much the White Cubes gives before unlocking the Blue Cube meter.

Once the Buyer Helper can buy no more, you can unequip it, as you won't need it any more. You can, if you want to, equip the Samurai, Ninja and/or Helper Helpers if you have them and the slots to use them to speed thing up somewhat.

Now, if it's not already, turn on the Auto Attack and Auto Next so that whenever the cubes fill up the Phase, they'd be used to attack, and when the Phase is cleared, you'd move to the next one automatically.

• Make good use of the Power of Cube! Make sure to invest all your White Cubes into the meter, only using them to boost Progress Speed whenever you have over 100x the amount needed to level up stored. And if you're lucky to get enough Blue, Green, Orange, Red or Gold cubes to be able to afford the first tier of their upgrades, invest in them.
  
• Choose your White Tick Speed wisely! The higher it is, the more White Cubes you'd get in each Phase... But also the more chances you'll get a higher tier cube instead.
  
• Don't give up! It may take a long time for your first NMC run to complete, but this would benefit you in the long run, as a long run would boost the Prestige bonus you'll get when you finally complete it.
  
• Get lucky! Those (Color) Cube nodes will sometimes drop their cubes into the Phase instead of a white one, which could increase the damage you deal a lot, especially if you manage to get a Red, a Gold or, if you have the node unlocked, a Platinum cube, and especially during Phase 10, where every bit of extra damage counts.