Well, you actually need all the skills you have to make the startup function and to thrive at a startup. We know. We are a young startup, but with experienced founders, including one that teaches entrepreneurship, and has a book published on the subject. Get in touch, if you are interested.
Let me see if I can structure the four most important types of skills you will need for helping the startup function, and for thriving at a startup:
You need to be persistent. And tolerant (of yourself, your colleagues in the startup, the results and the inevitable changes) while you are being persistent. Things take time. Things change. You hopefully have a straight-forward plan but be sure that you will have to change it over and over again. If you could map your plan graphically in time, you would see a line (your initial plan) and a path that resembles spaghetti all over it (your actual path). It is very important to build this and trust into the company culture early in the startup phase.
You need to know exactly what innovation, what product and which markets you are aiming at, and be able to express it concisely, precisely and comprehensively. Your startup's life (and hence your life) depends upon it. Your development, your market acceptance and your funding depends upon it. As important: Your internal synchronization, your energy depends upon it. If you don't have a concise, precise and comprehensive definition of what on earth the company is doing, you can not expect your colleagues to be pulling in the same direction. They may be very creative, maybe because you have been encouraging a creative culture, but they will be creating alternative paths that someone will have to clean up.
You need to have a business plan. It boils down to answering whether (and when) someone is willing to pay for all your efforts enough to cover the cost of your efforts, and leave profit enough to pay for people, events, fixes, returns, updates, and next generation innovations so that the next startup does not kick you off the market. And don't forget that a business plan will change because products, markets, customers, prices and the whole context of your operation will change.
And the last one is easy to express, difficult to practice: Be visionary and daring. why is this difficult? Well, because it may contradict practically all what we have said above: It contradicts planning and security and structure and precision etc. that most companies need. So be careful. Aim for an open enough mind-set (both for yourself and everybody else who wants to contribute) but have a contained relationship to it: react in a mindful manner, evolving, not revolting.
All startups need some luck in addition to all of the above, so good luck!
And do get in touch with us if you need someone to talk to as a startup. We are a technology company across disciplines like biomedicine and computer science, but we are a startup as well and we do like to help and share and learn from others whenever we have the opportunity