The major trick, IMHO, is not to grow. While a "normal" startup is focused on growing! growing! growing! a small company should instead think like a physical restaurant: "I have 10 tables * 4 seats. 4 waiters. Operate Lu-Fri 10 am - 6 pm. I can serve only up to 40 customers max per hour. My income will never be bigger than 40* Average meal. My income needs to be at minimum Costs + 3% profits". Then you see you have t…
This will not work for SaaS in most cases. Someone will copy your idea and with VC money grow more features and customers than you, forcing you into a tighter small niche if not oblivion. Restaurants have a captive market in terms of location and maximum number of competitors in the immediate vicinity. A web startup does not.
A lot of SaaS is just a simpler/different take on a big one. For example, mine is way less powerful than Freshbooks/amazon. I still live from it for the last 20 years with less than 100 customers (and a lot of time just less than 50).
Having a niche or just being available to your customers on the phone and solving the issue in the next minutes/hours is enough to keep customers and run your business.
Now, the big issue is that you are growing without the capacity to grow, and then you get a big competitor in your nose and you try to catch it. That is death.
Do not try to catch the bunny. Be the turtle and forget about the race, at all.