Before we dive into the equity,salary and such. Motivation and retention begins with the CEO.

Ask yourself what is the culture of the company? If you don't know anything about culture then start with the basics:
1. Do you value employee opinions? Do you ask for others opinions?
2. Do you encourage people to listen to employee problems? Do you listen to what other people have to say?
3. Do you encourage others to come up with ideas and suggestion?
4. Can you sell your dream?
5. Can you build consensus?
6. Hire people for their strengths and fix their weaknesses
7. Don't assume shit, always ask
8. Treat your interns like employees and mentor them
9. Have a clear vision and be able to articulate it
10. Can you admit when you are wrong? VERY IMPORTANT

So if you have a strong company culture this will help with new hires, motivate, and retain talent.

The frosting on the cake is free food/snacks, happy hours, company paid healthcare benefits, etc.