A majority of graze is going to be from using your unfocused bomb in bullet heavy parts of the stages. If you find that you're out of bombs in such portions, you should suicide for a fresh set of bombs. You'll probably gain a border after you bomb, but if there are times where you need to repeatedly bomb, just break your border to keep bombing.

There are certain parts in the stages where you want to prolong the non or spell as long as possible by not shooting. The reason why this is set on Hard difficulty is because it's the easiest to graze and survive for this achievement (Hard has just enough bullets to reach 80,000).

A full run through can be found below, but a more condensed version can be found in the lower sections of this guide (split by stage with clips). I've marked the minimum graze you should ideally have at the end of each stage.

Hyp has a bunch of non spells that you should bomb on:


Hyp's second spell is good for grazing:

Chen's nons are decent for grazing, you could bomb here for more graze but I think it's not that necessary to.


Chen's last spell is really good for graze:

Alice's non is amazing for graze, it's really long so make sure to use tons of bombs and all of the time:


Alice's third spell card is decent for graze:

Stage 4 is where you'll earn the most graze, the beginning starts off really well:


There will be tons of fairies to graze from throughout the stage, but when they all gather at the top make sure to use a bomb for those:


When the fox girls appear you can bomb for those too for graze:


Now the best part is Lily's nons are extremely good for graze, use as many bombs as possible!

Fox girls in this stage will throw out lots of bullets before Ran, use bombs for these:


Ran's nons are really good for graze, use as many bombs as possible:

Before the midboss shows up, the fairies here are good for grazing:


After the midboss, the ghost girls here are good for grazing:


Yuyuko's second spell card is great for grazing:


If you're cutting it close for graze, Yuyuko's "final" card can be grazed a lot: