Don't let pride get in the way. The Co-Pilot may be more current on instruments than you are and may be used to operating in a multi-crew environment. Use him/her to best advantage but remember that you're a team of two, not Captain and his little helper. Ask the Co-Pilot to speak up if he/she notices any errors and ommisions on your part. Brief him'her on exactly what you require, for example, "I'll expect you to call out check heights on the approach" or "I'll expect you to call approaching 3 DME". Confirm the facts, for example, "we'll be climbing to Altitude 5000' on this SID" and ensure that you're both in agreement. End the briefing with "Any questions?" Nowadays, CRM is part of the checkride assessment.