冘: movin' on

冘:  this 表外漢字 means something like "move on."  I can picture it as someone with broad shoulders or football pads, walking right at a fast pace. 

沈, sink:                   Movin' on under water.  Just not in a good direction.
枕, まくら (pillow):  Well, maybe the stuffing is wood chips or sawdust. 
                                  Movin' you on to dreamland.

冘沈枕

九か十のもの

卆は表外漢字ですが、「soldier」です。はい、but I find it easier (and funnier) to think of it as nine or ten.

砕, smash:  9 or 10 rocks out to smash 'most anything.
枠, frame:  9 or 10 trees can frame any view.  (It's sort of a
                    frame or bounding box.)
酔, drunk:  What you get after 9 or 10 drinks.
粋, chic:     You might just use rice or flour, but I use at least 9 or 10
                     types of grain.  Très chic!

砕枠酔粋

豸: 奇妙な動物

豸is 表外漢字, meaning (per Kanji Study) snake, bug IIRC, and badger.  I'll go with badger as it looks sort of like 豕 but with extra stuff at the top.  Teeth?  That helps with...

貇, which is also 表外漢字, and seems to mean "gnaw."  Which is what a critter might do with things it stops to stare at 艮 because they look like good 良い food 食べ物.

So after all that:

墾, cultivate:  One way to get land 土 ready for planting is to get critters 豸 to
                        gnaw on it  貇.  (Farmers do this with pigs, but maybe badgers
                        will work in a pinch.)
懇, cordial:     The warm fuzzy feeling a critter gets when you give it
                           something to gnaw.

Kanji: 墾懇.

我: It's all about ego this time

我, self:  a halberd with tassels.  Maybe I think I'm special so I decorate my halberd?  But I think it looks like (yet another) altar too.  Just a very halberd-like one.  That connotation will help with some of these derived symbols.
餓, starve:             My selfish self sees food and I'm starving.
義, righteousness: The sheep 羊 is a symbol of virtue; my self's virtue is my righteousness.
犠, sacrifice:         The cow counted for my righteousness is the one I sacrifice to the gods.
儀, ceremony:       But really a person can best touch his righteousness, and his soul, in ritual.
議, discussion:      Let's have some words about how awesomely righteous I am.

Kanji: 我餓義犠儀議.

卜: the divining rod

卜、単独で (by itself)、人名用漢字(kanji for proper names)です。  It's a divining rod, and looks like one.  Since there's no mention of water I can find, I think it's more general than the western version, which looks for water.

外, outside:  Magic happens at night, so that's when to look for a divining rod.
朴, crude:     A divining rod is a crude use of wood.
掛, suspend: The daring thief takes divining rod in hand to find the square jewels.
赴, proceed:  At a run, follow the divining rod to proceed to the treasure.
訃, obituary: Words written up as the thief goes to meet the divine.  He shouldn't have proceeded!

外朴掛赴訃.

斬: some gruesome 漢字

Let's be honest:  this set's mnemonics are gruesome.  But when your root is "beheading," I don't know what else you can do.
斬, beheading:    It's the French Revolution, and the cart is carrying the hapless
                                victim to the site with the man with the axe.
暫, temporarily:  Just for a short while, the beheading victim gets to see the sun.
漸, steadily:        And then, that splash of -- urk, too awful to say -- steadily streams out.

斬暫漸

十。。。九。。。八。。。

あけおめ！ことよろ！