I get so excited when I'm getting the suitcases down from the attic but then I don't actually pack until the day before, or the morning of if we're leaving very late. I do have a packing list though, and it doesn't change much from trip to trip.
When we were doing competition trips I also packed those bags, and it was a separate list. But either way I insist on no interruptions while I'm packing and now my daughter does the same. We basically have everything washed, mended if necessary and folded on the bed...and then you can see what you're missing or have too much of. I usually have one colour that everything will match with...and it's usually navy blue.

My daughter generally does light pink...you don't need to pack an entire rainbow for a trip, so if nothing matches that item it's out.
Bag fees are getting so expensive now from Canada, and many airlines are starting to charge for a carry on. If it was just about space I could live without the carry on, but we always put everything we will need for the first 24 hours in the carry ons...just in case. When they were competition trips we also put the dance outfits in the carry ons because there was no way to replace them in time for comp if they were lost or delayed.
My daughter now takes cheap jewelry for the trip, stuff she doesn't mind losing and leaves everything special at home.