Possible Clues:

• It's important to make a good one
• Opinion formed when shaking hands, perhaps
• Initial judgment
• Most of those in 1 down and 22 across offering snap judgement that lasts a lifetime
• Interviewee's consideration
• Job interview concern, or a hint to this puzzle's theme
• Lasting memory, perhaps
• The new dentist wanted to make a good ..
• It's good to make a good one
• Initial reaction