Considerate and helpful.
I worked with Shelley in the States, and eventually Rosie in the UK. Both were excellent customer service people. Shelley stayed late one night to accommodate a late submission because she remembered my deadline, but also the importance of including all files on the drive. One thing: tell your sales representative if you want to waive the signature at delivery. I didn't realize I should have done this, and it delayed delivery for a day.