1) not getting chickens sooner, then
2) getting chickens too soon, i.e. before coop was built, and
3) not getting more chickens, or building coop larger
More seriously, I'd say
1) getting started pullets via feed store. It just never occurred to me, tho it should've, they'd come debeaked. Mind, they seem to do just fine, but still.
2) trying to put an asphalt-shingled 3/4" plywood roof on an already barely-moveable tractor. Ended up taking it off (can barely lift just the roof without help!) and completely replacing it, urgh.
3) planning to use electric fencing to predator-proof tractor in our backyard, and indeed spending almost $200 buying electronet and charger, without stopping to think "is there anywhere I can actually stick in a ground rod that won't screw up my phone reception etcetera?" And of COURSE, there's nowhere right around the house that's far enough from buried utility lines to do it. Sigh. (Plan B: next year get more chickens, build large tractor for hawkproofing, and use the portable elctric fence stuff to house chickens in the front horsepasture.)
OTOH I have only got 3 chickens and only had them for 5 months, and I am confident that I have bijillions of much bigger mistakes ahead of me
Pat
2) getting chickens too soon, i.e. before coop was built, and
3) not getting more chickens, or building coop larger

More seriously, I'd say
1) getting started pullets via feed store. It just never occurred to me, tho it should've, they'd come debeaked. Mind, they seem to do just fine, but still.
2) trying to put an asphalt-shingled 3/4" plywood roof on an already barely-moveable tractor. Ended up taking it off (can barely lift just the roof without help!) and completely replacing it, urgh.
3) planning to use electric fencing to predator-proof tractor in our backyard, and indeed spending almost $200 buying electronet and charger, without stopping to think "is there anywhere I can actually stick in a ground rod that won't screw up my phone reception etcetera?" And of COURSE, there's nowhere right around the house that's far enough from buried utility lines to do it. Sigh. (Plan B: next year get more chickens, build large tractor for hawkproofing, and use the portable elctric fence stuff to house chickens in the front horsepasture.)
OTOH I have only got 3 chickens and only had them for 5 months, and I am confident that I have bijillions of much bigger mistakes ahead of me

Pat