One of the main features of a leader is strength. Not physically, but the power of ideas, spirit and charisma. A leader must have the energy to 'recharge' others. When people come to a leader, they have to feel more capable than without him. I did not study leadership specifically: I was always so passionate about what I was doing, and this compensated for my ignorance of specific techniques.
For me, the main criterion when selecting people for work is fire in the eyes. If a person is enterprising and has inner energy, it must be taken. She will definitely achieve something big: either great success or great defeat. Sometimes the same energy motivates people to develop further apart from my company. And yet I try to look for just such employees https://gtm-plus.com/when-staff-augmentation-is-best-option-for-startups/.