What you should wear for a headshot depends on the purpose of the headshot and the image you want to project. Here are some guidelines for different purposes:

1. **Professional/Business Headshots:**

- Wear business attire that would be appropriate for your industry.

- Opt for solid colors rather than busy patterns.

- Wear a well-fitted suit or blazer, and a shirt that contrasts with the jacket.

- Women can also wear a blouse or a professional dress.

- Avoid distracting jewelry. Keep it simple and classy.

2. **Acting Headshots:**

- Wear something that fits the character types you want to be cast as.

- Solid colors are still a good choice, but you can be a bit more creative.

- Keep makeup and hairstyles simple and natural.

- V-neck shirts and blouses are often flattering.

3. **Modeling Headshots:**

- Wear a simple, form-fitting shirt or top.

- Avoid patterns, logos, or graphics.

- Keep makeup natural.

- Women might opt for a subtle, classic look; men might go for a clean, sharp look.

4. **Social Media/Personal Branding:**

- Think about your personal brand and choose clothing that reflects it.

- Casual attire is usually appropriate.

- You can go with colors and styles that express your personality.

- If you have a signature style or accessory, consider including it.

5. **Academic/Author Headshots:**

- Wear clothing that reflects scholarly professionalism.

- For men, a blazer with a dress shirt or turtleneck can work.

- For women, a blouse with a blazer or a modest dress.

- Solid colors are preferable, with classic styles.

General Tips:

- Avoid neon colors or very bright colors that might reflect onto your skin.

- Make sure clothes are clean and well-ironed.

- Choose colors that complement your skin tone.

- Bring a few different shirts/tops to the shoot for variety.

- If you wear glasses, make sure they don’t create a glare in photos.

Remember, the goal is to have a headshot that represents you at your best and serves the purpose for which it is intended. Think about the impression you want to make, and dress accordingly. Lastly, feeling comfortable and confident in your chosen outfit will also reflect positively in your headshots.

The frequency with which you should update your headshots depends on various factors including the purpose of the headshots, changes in your appearance, and industry standards. Here are some general guidelines:

1. **Professionals and Corporate Executives**: Updating your headshots every 2-3 years is a good rule of thumb. If you have changed your look significantly (such as a major haircut, weight loss, or aging) or if you have a change in position, it's wise to get a new headshot sooner.

2. **Actors and Models**: The entertainment industry often requires more frequent updates. It’s important for actors and models to have headshots that accurately represent their current look. Updating your headshots annually or anytime you make a significant change in your appearance (e.g., haircut, hair color) is advisable.

3. **Authors and Academics**: For authors and academics, headshots can usually be updated less frequently, every 3-5 years. However, if you’re publishing a new book or achieving a significant milestone, it’s a good idea to have a current headshot.

4. **Social Media and Personal Branding**: If you are using your headshot for social media profiles, consider updating it whenever there is a significant change in your appearance or if your personal branding evolves. It's also good to keep the image fresh for your audience, so updating every 1-2 years can be beneficial.

5. **Real Estate Agents and Sales Professionals**: Sales professionals, especially those in real estate, should update their headshots fairly often, as your image is part of your selling point. Every 1-2 years is a common timeframe for these professionals.

6. **Job Seekers**: If you're actively looking for a job, make sure your headshot on professional networks like LinkedIn is current. This is especially important if you're transitioning careers or re-entering the job market after some time.

Remember, the goal of a headshot is to provide an accurate and positive representation of yourself. It should reflect your current appearance and align with the image you want to project in your respective field. If you feel that your headshot no longer does this, it’s time to update it.

Getting a headshot is a common practice in various professions and industries. Here are some facts about getting headshots:

1. **Purpose Variety**: Headshots are used for a range of purposes including professional profiles, acting portfolios, business websites, social media, book jackets, and press releases.

2. **First Impressions Matter**: For many, a headshot will be the first impression they have of you. This is especially true in the online world. A good headshot can make you appear more professional and trustworthy.

3. **Photographer's Skill Matters**: A skilled photographer is essential for a good headshot. They know how to use lighting, angles, and editing to make you look your best.

4. **Expression is Key**: The expression you wear in your headshot is crucial. For professional headshots, a slight, genuine smile is often best. It makes you appear approachable. Actors may need a range of expressions to show their range.

5. **Cost Varies**: The cost of getting professional headshots can vary widely depending on the photographer’s experience, location, and what’s included in the package.

6. **Preparation is Important**: Preparing for your headshot by getting a good night’s sleep, taking care of your skin, and choosing the right clothes can make a big difference in the quality of the final product.

7. **Resolution and Crop**: Headshots are typically close-ups of your face and shoulders. High-resolution photos are important, especially if they will be printed.

8. **Natural Light vs. Studio Light**: Natural light can produce stunning headshots, especially for more casual or creative shots. Studio lighting is often used for more formal or professional headshots.

9. **Post-Processing**: Almost all professional headshots will go through some degree of post-processing. This might include color correction, light adjustments, and blemish removal.

10. **Digital and Print Formats**: Depending on your needs, you may receive your headshots in various formats. High-resolution images are needed for print, while lower resolution might be sufficient for online use.

11. **Legal Rights**: Depending on your agreement with the photographer, you may or may not own the rights to your headshot images. Some photographers retain the rights and grant you a license to use them for specific purposes.

12. **Casting Directors’ Perspective**: For actors, it’s important to note that casting directors often look for authenticity in headshots. They want to see what you really look like on a very good day, not an overly airbrushed or glamorized version.

13. **Colors and Backgrounds**: Simple backgrounds and colors that complement your skin tone are generally best for headshots. The focus should be on your face, not the background or your clothing.

14. **Cultural Sensitivity**: In some cultures and industries, what is deemed appropriate attire or expression in a headshot may differ. It's important to be mindful of cultural norms and expectations.

Remember that a headshot often represents your personal brand and can play an important role in opening opportunities. Investing time and effort into getting a quality headshot is often well worth it.