How do you get your first clients for a new marketing agency?

I recently started a small marketing/creative agency with a few service offerings.

The problem is that I'm struggling to get my first few paying clients.

I've tried:

• Cold outreach
• Personalized pitches
• Researching businesses before contacting them
• Sending improvement ideas specific to their brand
• Networking with local business owners

I've had conversations and some interest, but very few people are willing to move forward and pay.

One challenge I'm facing is that I don't have a strong portfolio yet. Since I don't have many completed client projects, it's difficult to build trust and demonstrate results.

For those who have built agencies or freelancing businesses:

• How did you land your first 3–5 clients?
• Did you niche down or stay general in the beginning?
• How did you build a portfolio without existing clients?
• What outreach methods actually worked for you?
• If you were starting from zero today, what would you focus on first?

I'd appreciate any practical advice or lessons from your experience.

Thanks in advance.