All of this fit in my Tri-star for an 11-day trip to UK and Germany:
2 black ponte slacks (I recommend Eileen Fisher and JJill for packability)
2 cotton slacks
2 black sweaters in linen and wool (Eileen Fisher merino wool crepe is a traveler's dream and works for 3-4 seasons in Europe)
11 cotton-, silk- or linen-jersey sleeveless blouses/tees in white/beige
1 long-sleeved denim shirt
1 pair of black shoes
1 rain/wind slicker
Nightie, socks and undies
Make-up, scarves and jewelry (to break up all that black)
Gifts for my hosts

I wore a third sweater, cotton tee, cotton slacks and second pair of shoes for travel.

Everything fit in two large EC Pack-IT two-sided cubes, 1 half-size EC Pack-IT two-sided cube, one EC Pack-IT half tube and the Pack-It slim kit for toiletries. I did not buy the Tom Bihn cubes since I already have a huge stock of EC cubes and thought they would also work.

The Pack-it cube and a half cube fit one side of the Tri-star. A second pack-it cube, shoes and the pack-it tube fit the zippered side. The rain slicker, toiletries slim kit and various notebooks, converters, and small electronics all fit the middle of the Tri-star, along with my laptop.

I didn't have to wash anything besides undies and didn't iron anything because the packing cubes and Tri-star kept my clothing from wrinkling.