Sounds simple but.. when you hire a technical guy; hire/keep the ones that are smarter than you. This allows you to let it go. If you thrust them to doing a better job than you would, its easyer to not get in their way.
On HR vs core employee: if you have fulltime work for a core employee, get one asap. This frees up the time you need to build your bussiness instead.
Once the basic needs are met, many smart and talented people look for internal motivation. It doesn't matter if it is a small or a large company, as long as they are happy and satisfied. According to Daniel Pink's theory of motivation [0], there are 3 aspects of intrinsic motivation: 1. Autonomy - trust them, don't micromanage, let them take decisions 2. Mastery - allow them to get better and acquire skills 3. Purpose - give them a meaningful purpose and sell them your vision
Internal motivation may mean differently for different individuals, but I believe the above three aspects cover the most of it.
[0] https://en.wikipedia.org/wiki/Drive:_The_Surprising_Truth_Ab...