Ikea doesn't have to destroy your marriage
I've said it before, simply don't take your girlfriend/wife/SWMBO*. I've posted this 12 step plan before:
Step 1: Convince the girlfriend/wife/SWMBO* that going on a weekend is a bad idea and it's better to take an afternoon off when it's sunny out
Step 2: Convince the girlfriend/wife/SWMBO* that you got this and she doesn't need to come along.
Step 3: Use the website to locate all items and their locations at your Ikea location
Step 4: Go to the store
Step 5: STUDY THE MAP at the entrance. Locate where your items are and where the shortcuts are located, they're not all marked but they are all on the map. Plan a route
Step 6: Pick up your items
Step 7: Use the self checkout tills to minimize friendly chitchat and old folks trying to pay with haypennies
Step 8: Load up the car and go home
Step 9: Argue with the girlfriend/wife/SWMBO* over the stuff you "forgot" to add on the list and didn't bring
Step 10: Piss off girlfriend/wife/SWMBO* enough that she won't try to help assemble the stuff
Step 11: Assemble the stuff correctly, first time, without problem
Step 12: Show new furniture to girlfriend/wife/SWMBO* and make up for arguing.
*Strike through as appropriate.