carry coals to Newcastle
push against an open door
supernumerary
mug's game
plow the sands
toy with
piss in the wind
cut corners
bungle
get blood out of a stone
bring owls to Athens
nail Jell-O to a tree
piss up a rope
bugger up
misoccupy
necessity
take up the slack
impairment
deadening
weasel out
pick up the slack
constipation
stultification
botch
waste of time
futz
incapacitate
draw the short straw
fart
save
prerequisite
cushy number
make bricks without straw
polish a turd
bother
boondoggle
army volunteer
knack
overreach
blunt instrument
on its way out
stultify
chase a rainbow
stroll
castrate
piffle
kick at an open door
putter about
miss
pound sand
frugalize
piss something up the wall
lamely
play around
putter around
get over
have had it
fanny about
indispensable
keep off the streets
whistle in the wind
put a hat on a hat
lump
flatfoot
toss together
incapacitating
get the job done
pick
waltz
drive a coach and horses through
misdevote
manage
niggle
push string uphill
unprofessionalize
weasel
muddle along
press into service
wangle
paint oneself into a corner
bang one's head against a brick wall
overkill
hamstring
box oneself into a corner
doss around
road
doss about
futility
slight
wangling
unnecessity
cleave
run to waste
ill-suited
fritter
get over the line