You are not expected to fly the 747, or whatever, flawlessly the first time around. What they're lookin' for is:
- Deviations are corrected in a timely manner
- You show a certain degree of progression
- You make the right priorities
- You make good use of your sim partner (even if you are able to
fly it all by yourself)
- You have a minimum of knowledge about IFR flying / procedures
- You know all the checklists (probably sent to you by mail, right?)
Good luck!
Oh, one last thing: being an IP, you're used to detect and pick on other peoples' mistakes, take it easy on the guy/gal next to you when you're PNF / NFP (pilot not flying / non-flying pilot). You're a safety-pilot and must help him/her; not evaluate and grade him/her!