Photo Enhancement for Quality Poster

I need a photo fixed for a quality poster to hang. The poster will be 30" x 40".

Requirements:
- Remove blemishes or imperfections
- Improve resolution or overall quality
- Enhance or highlight the face or person in the photo

Ideal skills and experience:
- Proficiency in photo editing software (e.g., Photoshop)
- Experience in portrait retouching
- Ability to work with large image formats for high-quality prints

Please provide before and after samples of similar work. Looking forward to your bids!