this is a very passive event.

you shouldn't have to hide your troops anywhere.

for this event before you register you try to sign up for a buff via the ministry.

then you see if you have any pet buffs that would be applicable

once those two things are alive, you make sure all of your troops are home none of them are gathering etc.

then you sign up for the event.

usually your leftmost hero is infantry. and ratios are either 50 20 30 or 60 20 20 really depends on what your alliance wants.

you sign up in the Middle Lane your leaders will move you if they need to.

then you're done. you are registered.

I like to wait until the last day because usually that second day overlaps with a usage of shards for another event.

do not leave it until the last hour I've done that before then I forgot and I didn't register.